David Tennant returns as the Doctor, joined by Lindsay Duncan and Peter O’Brien in the second special of 2009.

It’s Mars, 2059. Bowie Base One. Last recorded message: “Don’t drink the water. Don’t even touch it. Not one drop.”

The Doctor heads to a human settlement on Mars in 2059 and is met by the wary locals, but they’re soon forced to trust him when they need his help to fight a terrible illness that is wreaking havoc throughout the colony.

Guest-starring the acclaimed Lindsay Duncan, The Waters Of Mars is set to be one of the scariest Tennant episodes to date, as a creeping infection beneath the Martian surface threatens not only the human race, but also the Doctor’s most fundamental beliefs – with terrifying results.

Lindsay plays Adelaide – the Doctor’s cleverest and most strong-minded companion yet. Neighbours and Casualty star Peter also guest-stars as Ed, Adelaide’s second-in-command at the base.

The Waters Of Mars is the second of four specials to screen throughout 2009.