"The more someone told him not to do something, the more he had to do it."
Elizabeth Weir[src]

Janus was a Lantean Ancient who lived on Atlantis in the Pegasus Galaxy 10,000 years ago. He was among the few surviving Lanteans who returned to Earth after the war with the Wraith, the species which he was partly responsible for creating.


Background information[]

Janus was one of the most well-known and brilliant Lantean scientists, and his inventions were never orthodox advancements. He took great pride in creating out-of-the-ordinary technological marvels, most of which were either banned or frowned upon by the Lantean Council. He installed a time machine in one of the many Puddle Jumpers in Atlantis, and hid many of his controversial inventions and research (such as a component of the Attero device) in his secret laboratory. He also designed a personal cloaking device and made use of Long-range communication devices and the stones that go with them. He was also one of the Ancients responsible for creating the Wraith and for bringing the giant squids to the frozen planet. (SGA: "Before I Sleep", "First Contact", "Identity", "From the Depths")


Janus offers his help to an alternate Elizabeth Weir to help save the city so that the future Atlantis expedition would be saved.

When Major John Sheppard and Dr. Radek Zelenka were killed when a Wraith Dart destroyed the Time Jumper and crashed into Lantea's ocean, Janus was able to save Dr. Elizabeth Weir and became her advocate when she met with the Lantean Council. While he defended Weir and argued on her behalf that she should be allowed to return to her own time and prevent the Atlantis expedition from falling into the same tragedy, High Counselors Moros and Melia refused, and Moros angrily condemned his experiments, ordering the Timeship destroyed and the city to be evacuated. (SGA: "Before I Sleep")

Refusing to allow the future Atlantis Expedition to walk into the same disaster she herself had faced, Weir pleaded to Janus to help her find a solution that would keep the expedition from repeating history and meeting the same fate. Janus agreed and, after doing some calculations, concluded that periodically rotating the Zero Point Modules would allow slightly more power to be available when the city was visited by the Atlantis expedition. Weir agreed to stay behind in the city to perform the task of sequentially rotating the ZPM's and Janus programmed a stasis pod to re-awaken Weir every 3,300 years or so to allow her to manually turn the ZPM's. He also programmed a Failsafe mechanism into the city; should power drop to such a critical level that the shield would fail the mechanism keeping the city at the bottom of the ocean would release, and the city would rise to the surface. Lastly, he blocked all gate addresses except for Earth so that no one except someone from Earth could dial Atlantis. (SGA: "Before I Sleep")


Janus smiles back at Dr. Weir as he steps through the Stargate.

Janus departed with the rest of the Lanteans taking with him the crystals that contained his research, with the hope that his efforts to save Atlantis for the future Atlantis Expedition would succeed. Sometime after arriving on Earth he rebuilt his timeship, which would later be used to destroy a Goa'uld mothership and eventually retrieve a Zero Point Module from Ra, which was later used to shield and save Atlantis from a Wraith attack. (SG1: "It's Good to Be King", "Moebius, Part 1", SGA: "Before I Sleep", "The Siege, Part 3")


Shortly after finding Project Arcturus, the Atlantis expedition discovered Janus' protege, Ikaros, a teenage genius who worked with Janus in developing Charybdis, a reality-warping supercomputer that they believed could be used to change history so that the Iratus bug would never evolve, thus preventing the Wraith from existing. However, Janus abandoned the plan because he believed that Ikaros was becoming too obsessed after his family was killed in a culling. (SGA: "Mirror Mirror")


While searching through Janus' lab, McKay found the plans for a personal cloaking device. However, he tells Doctor Jennifer Keller that he doesn't think Janus ever got around to actually making it. Despite this, after months of work in Janus' secret lab, the expedition recovers "tons" of Ancient technology that they still haven't finished cataloging months later. (SGA: "Identity")


Appearing in Teyla's dreams, an Ascended Doctor Elizabeth Weir indicated she had encountered Janus and that he had Ascended himself. She also indicated that Janus had told her of the truth of the Wraith's origin and that he had possibly told Doctor Daniel Jackson as well, but Jackson wouldn't have remembered it. (SGA: "Secrets")


While doing research on the squid-like beings on the frozen planet, the Atlantis expedition's biologists realized that they had actually been brought to the planet by Janus. It was theorized that Janus, who was one of the scientists responsible for the creation of the Wraith and had been trying to slow human aging, may have been using the squids to test whatever mechanism he intended to use.

After establishing communication with Old Hunter, one of the squids, he confirmed that Janus did in fact bring his people to the planet with Old Hunter being one of the squids originally brought by Janus. Janus brought the squids in one of the Ancients' vessels and taught the creatures to communicate so that he could learn about them, their lives and how their bodies worked. Janus experimented upon the squids to learn about how Ascension could be reached which some of the squids managed. The squids changed by Janus' experiments and their descendants gained extended lifespans and didn't die of old age, but they failed to gain many of the other abilities Janus had hoped for and Janus abandoned his experiments upon the squids and changed to experimenting upon humans instead, leading to the creation of the Wraith. Janus claimed that transporting the creatures back to their homeworld would be difficult and promised to return for them in time, but never came back. The squids seek out the expedition's help to fulfill Janus' promise and are able to provide the Stargate address of their homeworld. (SGA: "From the Depths")

Alternate timelines[]

In an alternate timeline, what was left of the Tau'ri after an Aschen bio-weapon devastated Earth found a laboratory on a planet where Janus had created many different time travel prototypes following his experiments with the Time Jumper. Among them were pods that used the Stargate itself as an unchanging reference point to time travel, making the pods glorified beaming devices. An alternate Jack O'Neill, his daughter Jade O'Neill and a Reetou named Ite-kh used the pods to travel back in time to 2003 to avert their future. After succeeding with the help of present SG-1 and Janus' devices, they returned to their time, but not before Jade sent one of the pods on an overload cycle to the planet where Janus' lab was. When the pod exploded, it disrupted the planet's DHD and made the Stargate inaccessible, preventing anyone from ever finding Janus' time travel devices. (Stargate SG-1: Relativity)

Known Inventions[]


Appearances for Janus

In chronological order:



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