|Played By:||Colm Meaney|
A ruthless Genii, disguising himself as a harmless farmer, Cowen is in fact the leader of an underground Genii military. When Sheppard and Rodney McKay discovered their underground bunker, Cowen had Sheppard's team taken prisoner and interrogated them. He was infuriated when he discovered that they had woken the Wraith from their sleep, and their plans to kill the Wraith as they slept was no longer feasible. However they overcame their differences and Cowen sent some Genii on a joint mission.
When they came back, with one Genii short, he revealed that he never intended to let them go, but double-cross them, and take their Puddle Jumper. However, Sheppard manages to escape by decloaking two more puddle-jumpers.
After learning the Atlantis Expedition are transferring to another planet temporarily, Cowen sends a team to the city to overtake it, however the team failed, resulting in the deaths of even more Genii in the process.
Staying underground, the Genii distribute wanted pictures for various members of the Atlantis expedition that are known to have the ability to activate Lantean technology. Kidnapping them one-by-one, he managed to lure Sheppard and his team in a trap, however ultimately, he was betrayed by his fellow Genii who freed Sheppard, and set a bomb, killing Cowen and his fellow military men.