4x25 - Ocean Girl

As Praxis again prepares to launch their nuclear torpedo at the pyramid, commandos storm ORCA allowing Shersheba and Malakat to seize control of the station. Convinced Charlie holds the key to defeating the red virus, Jason and Neri obtain a blood sample from him for testing. Jason returns to ORCA to find Shersheba in command. Suspicious of him, Shersheba asks Ilona to find out what he's up to. With all ORCA personnel confined to their quarters, Cass and Brett sneak through the air ducts to the lab so that they may test Charlie's blood for antibodies to the virus. Ilona overhears their plans and tells Shersheba who burst into the lab and seizes the cure to the red virus. Ilona and Shersheba return to the pyramid to tell Malakat of the cure, crazed with power Malakat reveals his true colours forcing Shersheba to flee with the cure taking it back to the Ocean Planet. Ilona joins Neri and Mera back on the island as Neri is resolved to sacrifice herself in order to destroy the pyramid.