Alias (2001)

S4E22 Before the Flood

Jack, Sydney, Irina, Vaughn, and Nadia jump into Sovogda with a mission to deactivate a massive red orb that’s transforming individuals into zombies. Meanwhile, at APO, Marshall and Weiss leverage the Blackwell Index to coerce a Russian minister into providing them with access codes for a satellite. They uncover that Elena is connecting to the satellite. A CIA agent named Brodien warns them about the Rambaldi device, which emits a subaudible frequency that permanently changes anyone who consumes it. As the team moves forward, Elena becomes aware of their presence.