S4·E23 The Countdown

With an attack against the aliens pending, all non-essential personnel are being evacuated from ORCA. Louis informs agent Shelby that Hauser has kept Ilona of the evacuation list which leads to Praxis discovering that she and her mother are both aliens. Louis also manages to be taken off the list prompting Brett and Cass to stay behind as well. Believing Malakat and his commandos to have evacuated the pyramid as promised, Jason and Neri go to the pyramid but, along with Mera, they are soon captured when Malakat and his commandos reappear from within the pyramid. The impending launch of the nuclear torpedo aimed at the pyramid is detected causing all those within the pyramid to flee. Frantic efforts on ORCA to stop the launch succeed but Helen admits responding not to Dianne but on orders from ""a higher power."" With the launch stopped Shersheba and Malakat return to the pyramid and use the golden ankh to activate it. Malakat's first order is to begin the melting of the polar ice caps.