David Tennant will have to fight creatures from Mars in his last days as Doctor Who.
Among those he takes on will be ex-soap actor Peter O'Brien, who played Shane Ramsay in Neighbours and renegade doctor Stitch in Casualty
He told reporters in Sydney he will appear as a villain in the story.
Glamorous actress Gemma Chan has also been lined up as a baddie.
A source said: "Peter and Gemma's evil characters are some of the final ones David will face before Matt Smith replaces him."