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Ladon Radim, leader of the Genii, from "Coup D'etat"
|Stargate Atlantis race|
|Base of operations||Genii Confederation|
|First appearance||"Underground" (2004)|
In the fictional universe of the science fiction television series Stargate Atlantis, the Genii are a human culture living in the Pegasus galaxy (see also: Human civilizations in Stargate Atlantis). Although they appear to be simple Amish-like farmers, the Genii are an advanced, militaristic society. In the series, they have been both enemies and allies to the Atlantis Expedition. Nevertheless, Teyla Emmagan believes that outside of Atlantis, they represent the galaxy's best hope of defeating the Wraith.
The Genii were once a great confederation of planets, but millennia ago Wraith attacks forced them into hiding to survive. They took shelter in city-sized underground bunkers left over from forgotten wars, concealing their technological advancements under the guise of being simple farmers so as to avoid Wraith attention. These bunkers are accessed via hatches hidden inside Genii dwellings, and intruders are swiftly dealt with. Generations ago, the Genii shot down a Wraith dart at great cost, giving them hope for resistance. They have since devoted a great deal of effort into developing nuclear weapons with which to strike back at the Wraith. The Genii possess significant military assets and maintain safehouses and supply caches throughout the Pegasus galaxy, watched over by caretakers. They also have a large network of spies and informants, such as amongst the Manarians, that allow them to keep an eye on their enemies.
The Atlantis Expedition are first introduced to the Genii by Teyla in "Underground", as a potential provider of foodstuffs for Atlantis. She describes them as "good farmers and fair traders", best known for their tava beans. During the talks, John Sheppard and Rodney McKay accidentally stumble upon a Genii bunker. Discussions of an alliance between the two peoples take place, but their relations sour when the Genii learn that their plan, a coordinated nuclear strike on the hive-ships during the Wraith hibernation cycle, are no longer feasible as the Atlantis team has awakened the Wraith early. Nevertheless, a joint mission is carried out, which ends in the Genii attempting unsuccessfully to betray the Atlanteans. The Genii subsequently launch an attack on Atlantis when the city is largely evacuated during a storm, but are eventually forced to retreat, losing more than 60 soldiers in the process. The Genii weather a Wraith culling later that year, managing to deactivate their reactors in time to avoid detection. They provide their prototype nuclear bombs to Atlantis for the defense of the city and to test viability. Dr. McKay discovers the prototypes are incomplete. He, along with Dr. Zelenka fix those issues. 
In the season 2 episode "Coup D'etat", the Genii experience a change of leadership after Ladon Radim assassinates Chief Cowen and his elite guard. Due to Dr. Carson Beckett's efforts in treating many Genii of radiation sickness, including Ladon's sister, his new Genii government is more favorable towards Atlantis. Radim has since helped the Atlantis Expedition, and offers Teyla and Ronon Dex a place with the Genii when they are temporarily evicted from Atlantis. According to Radim, the Genii still have several attacks planned that could cripple the Wraith. Not all Genii accept Ladon's leadership, including Acastus Kolya, and many members of the old guard become mercenaries. In "Harmony", Sheppard and McKay run afoul of a Genii operation to manipulate politics on another planet. Ladon claims not to be responsible for that. In "Inquisition" during Atlantis' trial they believe the Genii are behind it as with Atlantis gone, they'd become the military power behind the new Coalition of Planets which they are apparently a part of. If they had really planned it that way, it failed as Woolsey managed to win the trial partially due to convincing one judge of three that it was in the Genii's interest to let Atlantis be the military power in the Coalition, and bribing a second, knowing that the third would never vote in Atlantis' favor, since she blamed Atlantis for the loss of her family to the Asurans.
In "Underground", Dr. Rodney McKay estimates Genii technology to be sixty years behind that of Earth. The Genii have access to primitive computers and projectile firearms of various models. The Genii have directed much effort into developing nuclear weapons, with which they hope to strike at the Wraith during their hibernation cycle. They have had trouble separating Uranium 235 from 238, and in initiating fission in a supercritical mass. Genii medical technology is not as advanced as that of Earth, and many of their people suffer from radiation sickness due to inadequately shielded reactors. In "The Siege", the Genii provide their prototype nuclear bombs to Atlantis for use in defending the city. The incomplete prototypes are made functional by Dr. McKay and Dr. Zelenka. The Genii employ fully functional nuclear devices for the first time in "Coup D'etat".
Chief Cowen, played by Colm Meaney, is the leader of the Genii in the first two seasons of Stargate Atlantis. In "Underground", he agrees to an alliance with the Atlantis Expedition after John Sheppard and Rodney McKay stumble upon a Genii underground bunker. He authorizes a joint mission to obtain a Wraith data storage device from a hive-ship. At the end of the mission he attempts to double-cross the Atlantis team, but Sheppard anticipates his move and his team takes the data storage device. In "The Storm", Cowen orders Commander Acastus Kolya to launch an assault on Atlantis, despite Kolya's objections that his forces are not ready.
In "Coup D'etat", Cowen masterminds a plot to abduct an Atlantis team led by Major Lorne, in order to gain access to the ATA gene. He also sends Ladon Radim to Atlantis, apparently as the planner of a coup d'état against him, so as to lure Sheppard and his team into a trap. However, Ladon is actually planning to topple Cowen, and plants a nuclear bomb beneath the warehouse where Cowen has placed his operations. The bomb eliminates Cowen and his personal guard, leaving Radim the leader of the Genii.
Acastus Kolya, played by Robert Davi, is introduced in "The Storm" as a ruthless Genii military leader. For the first 3 seasons of the show, he would prove to be a persistent adversary of the Atlantis Expedition, and John Sheppard in particular.
In "The Storm" and "The Eye", Chief Cowen orders Kolya to take his soldiers on an invasion of Atlantis, which he had learned was being evacuated due to a hurricane. Kolya captures Elizabeth Weir and Rodney McKay and forces them to work on saving the city from the storm, while John Sheppard fights on his own against Kolya's forces. Sheppard eventually succeeds in killing 55 incoming Genii reinforcements by raising the Stargate shield, and Kolya orders a withdrawal when it seems the city will be destroyed by the storm. He attempts to take Weir back with him as a hostage, but Sheppard shoots him in the shoulder and he falls into the Stargate without her.
Following his defeat, Kolya falls from Cowen's graces. On his own initiative, he takes a small team to Dagan and captures Sheppard and his team, who are searching for a ZPM. After they discover the ZPM, Sheppard, Ford, and Teyla turn the tables on their captors. Sheppard spares the defenseless Kolya, but assures him that he would not be so forgiving next time. Kolya disappears afterward and is presumed dead; in "Coup D'etat" Ladon Radim believes that Cowen had him killed.
Kolya returns in "Common Ground", where he captures Sheppard with the intention of trading him for Radim and taking over the Genii government himself. Kolya uses a captive Wraith to torture Sheppard, having him feed on Sheppard over and over again. However, Sheppard and the Wraith work together to escape. With his base compromised Kolya leaves through the Stargate, though not before Sheppard contacts him on radio and promises to shoot him on sight should they ever meet again. In "Irresponsible", Kolya arrives to investigate Lucius Lavin, who possesses an Ancient personal shield. He discovers members of Sheppard's team in the town and captures them, but once again he is outmaneuvered by Sheppard (with Lucius' help). When Kolya refuses to surrender, Sheppard shoots him in a quick-draw shootout. He returns in "Remnants" but is revealed to just be an alien AI taking on his form to distract Sheppard and the real Kolya is in fact dead, Sheppard says Dr. Carson Beckett confirmed it after Sheppard shot him.
Ladon Radim, played by Ryan Robbins, first appears as Acastus Kolya's aide in "The Storm" and "The Eye". He oversees their operation to invade Atlantis from the control room; John Sheppard knocks him out in order to raise the Stargate shield, killing 55 en route Genii reinforcements. Radim retreats from the city along with the other Genii.
In "Coup D'etat", Radim contacts Atlantis with an offer of a ZPM in exchange for materiel support in a coup against Cowen. This is apparently revealed to be a ruse by Cowen after Sheppard and his team are captured while attempting to steal the ZPM. However, after Radim receives news that Dr. Beckett has cured his sister and the other Genii hostages on Atlantis of radiation sickness, he reveals that he has in fact been planning a coup after all (though his original plan was to let the Atlantis hostages die along with Cowen and his men). He then releases the Atlantis team before enacting his plan to kill Cowen and his elite guard with a hidden nuclear bomb. Radim takes over the Genii government, billing it as a "bloodless coup" as no deaths occurred on Genii territory.
After Sheppard is captured by Kolya in "Common Ground", Radim travels to Atlantis to assist, motivated in no small part by the prospect of neutralizing a threat to his nascent government. Kolya demands that Radim be handed over to him in exchange for Sheppard. However, Radim is able to locate Kolya's base, allowing Sheppard's rescue. Radim appears again in "The Return", to offer Ronon Dex and Teyla Emmagan a place with the Genii after the two are evicted from Atlantis by a group of Ancients. Although they turn down his offer, afterwards Teyla expresses to Ronon that working with the Genii might be the galaxy's best hope without the Atlantis Expedition.
Sora, played by Erin Chambers, is a Genii soldier and daughter of Tyrus. Teyla Emmagan has known her since she was a child, and considers them friends. In "Underground", Sora is unhappy to be left behind from a joint Atlantis-Genii mission to obtain a Wraith data storage device. After the team is forced to leave her father Tyrus behind on the Wraith hive-ship, Sora blames Teyla for his death.
In the two-part episode "The Storm" and "The Eye", Sora is part of Acastus Kolya's team sent to take Atlantis when the city is largely evacuated due to a hurricane. When she learns that Teyla has entered the city, she disobeys Kolya's orders and sets off to avenge her father's death. However, Teyla bests her in single combat, but refuses to kill her. Together, they help the injured Carson Beckett reach the safety of the control room before the storm hits. Afterwards, Sora is kept prisoner in Atlantis. In the original concept of "The Siege", she is returned to her people as part of the deal to obtain Genii-made fission bombs for the defense of Atlantis. However, the scene was cut due to time constraints.
- Athor: A friend to Acastus Kolya and the father of Idos, mentioned in "The Eye".
- Fortum (played by Jon Cuthbert): One of the mercenaries hired by Lucius Lavin in "Irresponsible".
- Haemon (played by Dean Wray): A former member of Chief Cowen's personal guard, who became a mercenary after Ladon Radim's coup. In "Irresponsible", Lucius Lavin hires Haemon and his men to fake an attack on his village, so that Lavin (who was protected by a personal shield) could defeat them and be seen as a hero. However, after Lavin refuses to pay Haemon the amount that they had agreed to, Haemon leads Acastus Kolya to the village.
- Idos: One of the Genii soldiers sent to Atlantis in "The Eye", killed by the Stargate shield activated by John Sheppard.
- Lanko: One of the mercenaries hired by Lucius Lavin in "Irresponsible".
- Cassel Massan: Ladon Radim's personal assistant, suspected to have leaked Genii codes to Kolya in "Common Ground".
- Prenum (played by Christopher Britton): An official who meets with Elizabeth Weir during the Wraith attack on Atlantis in "The Siege (Part 2)". He initially intends to ransom her back to the Atlantis Expedition, but she convinces him to provide the Expedition with the Genii prototype nuclear weapons as per their original agreement.
- Dahlia Radim (played by Sonja Bennett): The sister of Ladon Radim, seen in "Coup D'etat". As she is dying of radiation poisoning, she is one of the terminally ill Genii who volunteer to be sent to Atlantis as hostages, as part of an elaborate plan by her brother to oust Cowen from power. However, Dr. Carson Beckett is able to cure her and the others, causing Ladon to change his plans and release the Atlantis team prior to his coup.
- Pranos (played by Adrian Hough): Kolya's second in command during his mission to Dagan in "The Brotherhood".
- Tyrus (played by Ari Cohen): A Genii soldier who represented his people in their trades with the Athosians, appearing in "Underground". He is Sora's father. He joins a team from Atlantis in a joint mission to retrieve a data-storage device from a Wraith Hive Ship. During the mission, he shoots a Wraith victim to keep him from drawing attention, disturbing Teyla. Teyla is forced to leave Tyrus behind after he is hit by a Wraith stunner; thus, Sora holds her responsible for Tyrus' death.
- "The Return" (Stargate Atlantis)
- "Underground" (Stargate Atlantis)
- "The Lost Boys" (Stargate Atlantis)
- "The Storm" (Stargate Atlantis)
- "The Siege" (Stargate Atlantis)
- "Coup D'etat" (Stargate Atlantis)
- "The Eye" (Stargate Atlantis)
- "Common Ground" (Stargate Atlantis)
- "Irresponsible" (Stargate Atlantis)
- "The Brotherhood"