One-off special. The Time Lord is caught in a terrifying situation when he visits one of the fixed points in time and space, the disaster that hit Bowie Base One on Mars in 2059. As he tries to come to terms with the prophecy that his present incarnation is soon to die, he starts to consider the possibility of altering the fundamental rules of time and space - with the support of strong-minded commander Adelaide. Starring David Tennant, with Lindsay Duncan and Peter O'Brien SUB AD HD