Zelenka recurs in all five seasons of "Stargate Atlantis" and is also among the "Atlantis" characters to appear in the "Stargate SG-1" crossover episode "The Pegasus Project". In his first appearance in the early "Atlantis" season 1 episode "Thirty-Eight Minutes", Zelenka helps devise a plan to free Major Sheppard's team including Dr. McKay from a potentially lethal technical problem. After a first short collaboration in "Suspicion", Zelenka and McKay are the driving forces in finding a solution to protect the city of Atlantis from a massive hurricane in "The Storm".