Broadcast: Friday 22nd August 2014
6:30am-7:00am AEST (20:30 GMT) < > « »
SyFy (Australia) (adverts during broadcast)

Featuring: Tom Baker, Louise Jameson, John Leeson, John Leeson, Frederick Jaeger, Michael Sheard

While answering a mayday from Saturn's largest moon, Titan, the TARDIS passes through a mysterious cloud. His companion Leela senses a malevolent presence, which turns out to be The Swarm (an intelligent space virus). The Swarm infects the Doctor, starting a struggle for control of his mind.
Synopsis Source: Syfy Site Listing