The Stargate might be the greatest storytelling device in all of science fiction. Our modern-day heroes don’t need a ship to travel the galaxy — just dial up this big, ancient ring and step through to another planet.

In the mythology of the franchise the Stargate network was built millions of years ago by a race of beings we call the Ancients. Made of the powerful mineral naquadah, the gate uses an artificial wormhole to connect two active gates through subspace. But there are limitations here, of course: the rules of Stargates dictate that travel is strictly one-way, a wormhole can be kept open for a maximum of 38 minutes, and you absolutely cannot use a Stargate to travel back in time. Right?!

As the writers of the TV series looked for new ways to tell stories, some of the most interesting and engaging came from what happens when the Stargate itself … breaks. Stargate Command, the Atlantis expedition, and the Destiny crew know how to use the gate to accomplish their mission on an ordinary day. But what about when things go haywire, and the Stargate itself becomes the problem that needs to be overcome?

By our count, so far Stargate has told these cool gate malfunction stories a whopping 19 times — and they are some of our favorite episodes ever. We’ll take these in order, starting all the way back with the first Stargate hiccup in the freshman season of Stargate SG-1.

WORMHOLE JUMP

“Solitudes” (SG-1 Season 1)

SG-1 is forced to gate home after their position at the Stargate comes under fire. Enemy forces in the distance are shooting toward the Stargate with high-powered energy weapons, and Teal’c and Daniel barely make it back to the S.G.C. alive. But when the gate shuts down and they look around … Colonel O’Neill and Captain Carter are nowhere to be found.

After Jack and Sam wake up in a frozen cavern and are unable to dial their Stargate out, their teammates eventually discover what has happened: the energy strike on the Stargate caused the destination end of the wormhole to jump from the S.G.C. to the next closest Stargate! In this case, that gate happens to be on Earth — lost eons ago beneath the ice of Antarctica.

GRAVITY WELL

“A Matter of Time” (SG-1 Season 2)

SG-10 rushes back to the Stargate in a panic, trying to dial back to Earth … but team commander Henry Boyd knows they are doomed. The planet is very near the event horizon of a newly formed black hole, and time on the planet is slowing down. They can’t keep the Stargate active long enough to step through. After the S.G.C. redials the planet to try and figure out what is going on, they find that they cannot shut down the Stargate. And the black hole on the other end can power the connection indefinitely, blowing past the 38-minute window.

To make matters much worse, even though nothing should be able to come through an outgoing wormhole, the black hole’s gravity is beginning to affect Earth. Time slows down inside the base (brilliantly explained by writer Brad Wright as a “lensing effect” caused by the gate, where the warping of space-time happens in advance of the gravity field causing it). To save the planet the team takes a lesson from “Solitudes,” aiming a shaped explosive charge at the Stargate to force the wormhole to skip to a different planet.

TIME TRAVEL

“1969” (SG-1 Season 2)

Seeing as how the Stargate makes use of artificial wormholes through subspace, it was inevitable that the show’s writers would find all kinds of interesting ways for the technology to go wrong. So why not that classic science fiction staple — time travel? SG-1 is sent back to Earth in the year 1969 and must locate the Stargate, avoid changing history, and find a way back to the future.

“1969” taught us a very important lesson about gate travel, which the writers would use for several future stories: If the wormhole passes too close to an active solar flare, its magnetic field can bend the course of the wormhole through subspace time. In this case the wormhole bent back to its sending gate — so SG-1 left Earth in 1999 and arrived through the very same Stargate. After they stepped through into the past the gate vanished, which Carter hypothesizes could mean that the team momentarily occupied both time zones.

TIME LOOPING

“Window of Opportunity” (SG-1 Season 4)

The Ancients built the Stargate network countless millennia ago, so leave it to Ancient scientists to figure out clever ways to hack the technology to do things Stargates were never meant to do. In this episode SG-1 finds an alien archaeologist studying advanced technology near the gate on a desolate world. Once home to a colony of Ancients, their civilization apparently died of a plague for which they could never find a cure.

The device, it turns out, was made to manipulate space-time — probably to give them more time to try and find a cure to their affliction. It uses the Stargate to connect 14 different worlds, forming a bubble in which time resets on a loop every 10 hours. After reliving the same day over and over, and over and over, and over again, seemingly for weeks, Colonel O’Neill and Teal’c finally convince the alien scientist to shut down the device.

WATERLOGGED

“Watergate” (SG-1 Season 4)

The rogue N.I.D. used Earth’s second Stargate in secret to come and go without the S.G.C.’s knowledge (“Touchstone”). That gate came with a D.H.D., and while the dialing device was connected the beta gate took priority for receiving incoming wormholes. Russia ended up exploiting this trick when they acquired their own Stargate and D.H.D.

But after operating in secret for about a month the Russian Stargate program ended in disaster. Everyone at the Siberian facility was killed, and the gate was stuck on — for hours, then days. Unable to use their own Stargate in Cheyenne Mountain, SG-1 is called in to resolve the situation. They find the Stargate connected to a water planet with unusual energy readings. An ocean of energy is powering the wormhole from the receiving side, and the strong signal from a Russian drone transmitting back through the gate is enough to hold the wormhole open.

Sam and Daniel take a mini-submarine through the gate, along with Russia’s Dr. Svetlana Markov (played by Star Trek’s Marina Sirtis), retrieving the drone and closing the gate. But then there’s the little matter of getting home again, surrounded by an ocean of what are in fact living beings.

MESSAGE TO THE PAST

“2010” (SG-1 Season 4)

It’s ten years into the future, and Earth is at peace after an advance race called the Aschen established a treaty, helped us defeat the Goa’uld, and offered their technology for the betterment of all of society. But this future version of SG-1 discovers that there is a sinister catch to all this benevolence: the Aschen’s medical technology has sterilized most of Earth’s population. In truth, this is a slow conquest.

The Stargate “malfunction” here comes in the form of a bold plan to undo the past and change history. With the Aschen’s advanced solar monitoring technology they can actually predict the magnitude and precise location of pending solar flares. The team sacrifices themselves to reach the Stargate, dial an address they know will cause the wormhole to bend backward in time, and send through a warning to prevent their past selves from ever meeting the Aschen.

UNFORCED ERROR

“Red Sky” (SG-1 Season 5)

It took 15 years and two supercomputers for Samantha Carter and a team of engineers to MacGyver a system that could access the Stargate’s systems and dial it without a D.H.D. But that meant that Stargate Command was sometimes able to connect to planets they really shouldn’t be able to … by overriding certain safety protocols. Turns out the Stargate isn’t designed to create wormholes that do things like pass right through a star.

That’s how SG-1 ends up dooming the people of K’Tau — brute forcing a connection instead of waiting for the planet to be in a different orbital position. As a result the K’Tau sun is contaminated and red-shifts, threatening to destroy the entire ecosystem. The team must find a way to fix the problem after the Asgard refuse to intervene. Maybe next time let’s not blow past those safety protocols that the Ancients were smart enough to program in.

TEAL’C IN THE MACHINE

“48 Hours” (SG-1 Season 5)

Things seem hopeless for Teal’c after he fails to emerge from the wormhole on Earth and the Stargate shuts down. Teal’c shot down an enemy Al’kesh on the other side, and he definitely made it though the gate … before the ship fell out of the sky and crashed into it. Carter is wise enough to avoid redialing the Stargate to look for him, realizing that Teal’c’s energy pattern is still being held within the Stargate’s internal systems. If the gate is dialed again, the buffer will be wiped and their friend will be lost forever.

“48 Hours” is the episode that finally explained the gate’s operation in some detail. Rather than physically stepping through a wormhole, the gate functions more like Star Trek’s transporters — converting a traveler to energy and sending that through, which the gate on the other side reconstitutes into matter in the blink of an eye.

With help from a Goa’uld prisoner, and borrowing Russia’s D.H.D., SG-1 is able to fool the Stargate into forming an event horizon without a new wormhole — allowing Teal’c to emerge safely.

POWER BUILD-UP

“Redemption” (SG-1 Season 6)

One reason Anubis was such a formidable enemy when he first stepped out of the shadows was his (at the time) inexplicable acquisition of advanced technology left behind by the Ancients, along with the ability to use it. One such device was a weapon aimed squarely at Earth: a device that fires a sustained energy beam through the wormhole, able to maintain the wormhole far past the 38-minute window. Even with the iris closed the weapon causes Earth’s Stargate to slowly build up a charge — just a trickle of power, but growing to dangerous levels over several days.

Once the S.G.C. discovers the extra power transfer it becomes clear that Earth is under attack. The Stargate is effectively one giant superconductor, but with its power storage pushed beyond capacity the gate itself can become supercharged … and explode. For two episodes SG-1 scrambles to find a way to disconnect the wormhole, or even transport the active Stargate away from Earth.

While the planet is finally saved, the Stargate is destroyed. (It is replaced by Russia’s Stargate for the remainder of the series.) Fortunately Teal’c, Bra’tac, and Rya’c manage to locate Anubis’s weapon and destroy it, so he can never use this particular trick again.

COMPUTER VIRUS

“Avenger 2.0” (SG-1 Season 7)

Dr. Jay Felger is trying to prove his usefulness to Stargate Command, and he actually hits on an idea that is kind of brilliant. Even Samantha Carter thinks it’s worth a try: Felger has developed “Avenger,” a computer virus that can be transmitted through the wormhole to a receiving gate, effectively scrambling its D.H.D. (specifically, the coordinates associated with each symbol) and knocking an enemy gate off the network.

But Carter picks the wrong Goa’uld to pick on. They test the virus on P5S-117, the location of one of Baal’s most important naquadah mines. After more and more planets start to go offline, it becomes clear that the entire Stargate network could be disabled! Carter and Felger gate into enemy territory to try and correct the problem. After plugging into the D.H.D. they discover the cause: Baal discovered the virus and modified it, triggering a network-wide update procedure to disable the gates — using his fleet of ships to then move against his enemies.

SUPERGATE MAKER

“Beachhead” (SG-1 Season 9)

Here’s another instance where a wormhole is maintained for days on end because one end of the connection is powered by a black hole (or so Sam speculates). In this instance that’s in the Ori home galaxy, and the Ori are using it to create a beachhead in the Milky Way for their invasion fleet. They goad Earth and its Jaffa allies into attacking the Prior at the Stargate on the planet Kallana, using the power to juice a shield that eventually envelops the entire planet — collapsing it into a singularity. With a black hole on both sides, the Ori can maintain a wormhole connection indefinitely.

Of course, one little Stargate inside a black hole isn’t going to be of much use in sending through large warships. So before the planet collapses the Ori’s followers send many dozens of segments through the Stargate, which fly into orbit and arrange themselves in a circle. Once complete, the black hole will power the first Supergate — a massive gate in space, big enough to accommodate a capital ship from the Ori galaxy.

It’s a complex and dastardly plan, but really the only thing we can actually call a “malfunction” here is that the Ori know how to use black holes to keep a wormhole open — and to power a massive Stargate. Thanks to some quick thinking by Vala Mal Doran, this first attempt at a Supergate is destroyed. But the Ori have a proof of concept on the drawing board.

SECURITY MEASURES

“Prototype” (SG-1 Season 9)

It looks like the Stargate is malfunctioning again when Carter and SG-5 step through and realize they’re on the wrong planet — not that they mis-dialed, but the Stargate actually sent them to a different planet than the one they dialed. How is that even possible?

After some investigation they discover the cause: a security system that Anubis set up on P3X-584, to protect a super-secret experiment (Khalek). If a connecting Stargate does not transmit the proper code the planet’s gate stores the incoming traveler in its buffer, redials another world, and dumps them into the new wormhole — what Mitchell dubs “interstellar call forwarding.” From the team’s perspective they step into the gate on Earth and exit on the wrong planet.

It’s not necessarily a malfunction per se, but a clever hack on Anubis’s gate that created the appearance of one.

COPY MACHINE

“Ripple Effect” (SG-1 Season 9)

What’s worse than accidental time travel, a gate you can’t shut down, or one that sends you to the wrong planet? How about when the Stargate keeps sending duplicates of SG-1 to Earth … over, and over, and over again?! That’s the premise of “Ripple Effect,” as Stargate Command plays host to 16 different SG-1 teams from parallel realities. There’s no obvious reason why the Stargate would be pulling them from their own universes — but fortunately there are plenty of Carters to put their heads together!

In a nutshell: the black hole left behind by the Ori’s collapse of Kallana has become an interdimensional funnel, drawing in numerous wormholes in other universes that pass close to its location. When another SG-1 join our heroes on a mission on board the Prometheus to try and sort out the problem (with a little help from an Asgard time dilation device), our team discovers the truth. The other SG-1 did this on purpose, using the black hole to punch through to our universe. (They hoped to act innocent and use the opportunity to swipe a Zero Point Module from Atlantis.)

Fortunately the problem is reversed by duplicating what the evil SG-1 did to get here: dialing to a planet on the other side of the black hole and blasting the Stargate with a calibrated energy weapon. All the different SG-1s are able to return to their own realities.

SUPERGATE SKIP

“The Pegasus Project” (SG-1 Season 10)

This is a “malfunction” of a different sort — a plan deliberately executed by the team in order to take the Ori’s Supergate out of play. In this case SG-1 uses its accumulated knowledge to actually cause the malfunctions, first powering a wormhole with a black hole and then using a perfectly timed explosion to make the wormhole skip to another gate.

By Season Ten the Ori have built a new Supergate and established their beachhead, invading the Milky Way by ship. To try and cut off the enemy from reinforcements, SG-1 hatches a genius plan: they travel to the Pegasus Galaxy on board the Odyssey, find a black hole to power an 8-chevron connection to a Stargate that Teal’c has planted next to the Supergate, then use a strategically placed detonation to force that wormhole to jump to the Supergate — holding it open so the Ori can’t use it any more. And hey, because nothing is ever easy, how about we destroy a Wraith ship and an Ori warship while we’re doing it?

BAD TIMELINE

“The Last Man” (Atlantis Season 4)

The Atlantis expedition gets its own dose of accidental time travel in the fourth season finale, when Lt. Colonel John Sheppard steps through the Stargate and finds himself alone in a very desolate Atlantis — an astounding 48,000 years in the future! The city is abandoned, the ocean is gone … and a holographic McKay explains how history went very, very badly after Sheppard was lost.

This is another case of the wormhole passing too close to a solar flare. But instead of the 30 years that SG-1 traveled backward in time, we discover that the magnetic interference can also bend a wormhole many thousands of years off course in its journey through subspace time. Fortunately McKay has a plan to get John back to the past, though he’ll have to brave a sandstorm and a few hundred years in stasis to get there.

WEAPONIZED TIME TRAVEL

Stargate: Continuum

SG-1 aren’t the only ones who can use solar flares to travel through time. The fallen System Lord Baal also knows of this gate malfunction (possibly because he gained access to Stargate Command’s computer in “Insiders”). And with Earth and the Tok’ra closing in he enacts a plan to rewrite galactic history. Baal builds a time machine on the planet Praxeon, using a network of satellites monitoring hundreds of stars and transmitting real-time telemetry through subspace. As any given solar flare creates a brief window for time travel, Baal’s supercomputer can calculate the time and place a wormhole passing that star will end up.

Baal uses his evil genius to arrive on Earth in 1939, where he causes Earth’s Stargate to be lost during its trans-Atlantic crossing — then he sets about using his knowledge of the next seven decades to conquer the other System Lords and force them to bend the knee. To escape the final destruction of Earth, SG-1 finds their way to Praxeon and uses the technology to travel to a point before Baal’s arrival. Cameron Mitchell winds up on Earth in the 1920s, giving him plenty of time to get into position and take out Baal when he arrives. Timeline fixed!

EXPLODING STARGATES

“First Contact” and “The Lost Tribe” (Atlantis Season 5)

The Ancients didn’t just invent the Stargates, and weapons to destroy Stargates, and devices to create time loops, and so much more tech they left littered around two galaxies. Their scientists engaged in other questionable experiments that also used subspace — including weapons to use against the Wraith, at a time when the war against the vampiric creatures seemed more and more hopeless.

One such project was the Attero Device, created by Janus to stop the Wraith in their tracks. By generating a specific frequency of subspace turbulence, any hive ship that tried to enter hyperspace would be destroyed instantly. So why didn’t it work? After a few brutal days Janus learned that Attero was also causing Stargates to charge and explode whenever they are dialed — threatening countless millions of innocent lives throughout the Pegasus Galaxy.

He shut down the project … but 10,000 years later a group of rogue Asgard reactivated it, to achieve their own selfish ends. The Atlantis team and Daniel Jackson managed to deactivate the device and send the Asgard running. But one cost was the Atlantis gate itself, which exploded and would have taken out the entire city if not for the quick work of Dr. Zelenka and Colonel Sheppard.

MESSAGE FROM YOURSELF

“Time” (SGU Season 1)

Several months after boarding Destiny on its course through distant galaxies, the reluctant crew from Earth stumbled into a disturbing time paradox of their own. When they stop to visit a planet they find one of their own kinos near the Stargate, filled with recordings of themselves — a near future where they all died horrifically.

As they try not to repeat their own mistakes and repeat history, the crew discover that they have been infected by a fast-growing parasite from the alien water they harvested weeks earlier (“Water”). But there is a potential cure: the venom of a hostile and nocturnal creature on the jungle planet they are now approaching. They’ll have to survive the creatures themselves in order to save themselves.

So where did this future kino come from? After the team arrived on the jungle planet the Stargate started fritzing. The event horizon was unstable, and Dr. Rush wass unable to raise Destiny on the radio. Finally Lt. Scott recorded a message for Destiny and tossed the kino through, hoping they would signal that it is safe for them to return. But, unbeknownst to the team, the gate was now being affected by a solar flare — and their kino arrived back on the jungle planet, in the past.

And after watching all of this, piecing together what happened and where the cure is to be found, and seeing everyone around him die again, Lt. Scott realizes that they will have to repeat the loop again … and he records a new message for Destiny. “You don’t have much time. Act now, or you are all going to die.”

DESTINY’S CHILDREN

“Twin Destinies” and “Common Descent” (SGU Season 2)

If you thought a wormhole passing close to a solar flare was a bad idea … how about trying to dial the Stargate to Earth and establish a wormhole while instead a star? Destiny uses stellar matter to refuel, and Colonel Telford is convinced that they can use this massive infusion of power to dial the 9-chevron address and get everyone back home. Against the advice of Dr. Rush he executes his plan, and everyone but Rush go through the gate.

It’s a terrible idea, of course, and Telford is the only one to make it to Earth. After just a few seconds the gravimetric forces of the star impact the wormhole’s trajectory, sending the rest of the crew to the closest planet with a Stargate … 2,000 years in the past. Rush and the ship, meanwhile, are also pushed several hours into past, setting up a fateful rendezvous with himself. He warns them not to enact Telford’s plan, and the second Destiny falls into the star after the crew salvage it for spare parts.

The impacts of this Stargate malfunction continue to reverberate, however. Months later Destiny encounters a colony of human beings — their own descendants, or rather those of the other crew stranded two millennia ago. Now the Novans have grown into an advanced, space-faring civilization, though one that had to abandon their homeworld when natural disasters rendered it uninhabitable.

Which Stargate malfunction story is your favorite? Put it in the comments below!