David Tennant's Tenth Doctor is set to meet Peter Davison's Fifth Doctor in a special scene commissioned for BBC One's Children in Need.
The scene, entitled Time Crash, was written by award winning Doctor Who writer Steven Moffatt, and will transmit as part of the Children in Need fund raising evening on Friday 16 November 2007.
And, if it follows on chronologically (which we can assume it does otherwise it would make no sense!) then it'll either be in the TARDIS, which will have a ship stuck through the wall, or actually on the Titanic! But if it is, I doubt we shall meet Astrid just yet.
Additional: Just found this on a website. Enjoy it!
More photos and stuff.... (added 6th November)
The pair teamed up for the special, which will be screened as part of the BBC's Children in Need charity night, in a programme which sees the two doctors team up to thwart an alien.
He said: "I only found out afterwards that he was a fan of my Doctor, because he sent me a very nice text saying that he was at first a bit tongue-tied.
"We were feeling the same, in a way, for different reasons.... But it was enormous fun working with him, because I go quite fast when I'm acting - it's quite energetic, and he is as well."
Davison succeeded Tom Baker (the Fourth Doctor), at the age 29. He was and still is the youngest actor to assume the lead role.
(Taken from the Daily Mail)