Following their first encounter with the Atlantis expedition, Cowen orders Commander Acastus Kolya to create a strike force prepared to attack the people of Atlantis. After hearing from the Manarians that Atlantis would be virtually abandoned due to the Lantean storm, Cowen ordered Kolya to raid Atlantis for the supplies they needed despite Kolya's insistence that his strike force was not yet ready for such a mission.
The strike force is able to force a drunk Athosian to send the IDC needed for Atlantis' Stargate shield to be lowered and tell the Marines in Atlantis that Manaria has suffered a Wraith attack and they must come through the Stargate right away. Disguised as refugees from an attack, the strike force is able to successfully invade Atlantis where Kolya murders the two Marines and captures Doctors Elizabeth Weir and Rodney McKay. Kolya demands all of Atlantis' C-4, all of their medical supplies, a Puddle Jumper and the Wraith data storage device taken from the Genii. McKay manages to discreetly alert Major John Sheppard, still secretly loose in the city, to Kolya's demands and he hides the C-4 and leaves a Tau'ri radio to communicate with Kolya.
By that point, Kolya has learned of the plan to save Atlantis and demands that Sheppard disable the last grounding station so that the Genii can have the city, promising to spare their lives in exchange. Instead, Sheppard ambushes and kills two of the strike force using a life signs detector. Kolya nearly kills Weir in retaliation, but is talked out of it by McKay. While Kolya forces Weir and McKay to repair the damaged grounding station, Genii scientist Ladon Radim uses the city sensors to lead three of the strike force in a hunt for Sheppard. After Sheppard ambushes and kills the three, Kolya calls for a full company of reinforcements from the Genii. Sheppard is able to disable the Naquadah generators powering the Control Tower and the grounding station, further hampering the strike force's efforts. When the reinforcements arrive, Sheppard knocks Ladon unconscious and activates the Stargate shield, locking out the controls with his personal command code. Escaping, Sheppard kills another strike force member with blind fire while only five more Genii soldiers make it through the Stargate. A further sixty die against the Stargate shield.
With Atlantis coming under the full force of the storm and still wanting Atlantis intact, Kolya contacts Sheppard and threatens to kill Weir and McKay if he fails to repair the generator powering the grounding station. At the generator, Sheppard is ambushed by two of the strike force before he can repair the generator, but the two men are shot with a Wraith stunner rifle by Lieutenant Aiden Ford, allowing Sheppard to repair the generator. With the grounding station back online, McKay is able to separate the grounding rods and Kolya orders his men to fall back to the Stargate. Sheppard attempts to set up an ambush, but the ambush fails when Sora Tyrus knocks Doctor Carson Beckett unconscious and fights Teyla Emmagan.
McKay ultimately fakes that the plan to power the Atlantis' shield with lightning has failed and with a tsunami approaching, Kolya decides to retreat with his strike force through the Stargate with Weir and McKay as prisoners. A few members of the strike force make it through the Stargate with some of the expedition's stolen supplies, but the rest are ambushed by Ford and Sheppard. Several more strike force members are killed with only Ladon making it through the Stargate unharmed after Sheppard and Ford open fire. Kolya tries to use Weir as a hostage during his escape, but is wounded in the shoulder by Sheppard and is forced to leave Weir behind as he falls through the Stargate.
Following the Genii's disastrous invasion of Atlantis, the only known survivors of the strike force are Kolya, Ladon, Sora, who is taken captive on Atlantis after being beaten by Teyla and a few members who escaped through the Stargate before Sheppard and Ford started firing. The strike force is disbanded following its failure and the death of most of its members. (SGA: "The Storm", "The Eye")
When Ladon Radim contacts Atlantis for help with his planned coup, he is recognized as a member of the strike force from the invasion. Ladon tells the Atlantis expedition that he was merely following orders during his time on the strike force and it was never personal for him. (SGA: "Coup D'etat")
After Ladon takes control of the Genii, Kolya kidnaps Lt. Colonel John Sheppard and attempts to trade him for Ladon. When Kolya contacts Atlantis, Teyla Emmagan identifies him to Ronon Dex as the leader of the strike force that invaded Atlantis and which Ladon had also been a part of. While discussing the matter with the expedition, Ladon tells them that the failure of the strike force shattered Kolya's standing with the Genii and forced him from Cowen's inner circle. (SGA: "Common Ground")