The Doctor and Martha face a desperate race against time to save the crew of a spaceship that is on course to hit the sun. The pair have only 42 minutes to prevent a collision - and their task is made even more difficult by crew members who have been possessed by a mysterious force and a gang of saboteurs. Former EastEnders actress Michelle Collins and ex-Hollyoaks star Elize du Toit appear alongside David Tennant and Freema Agyeman