Matt Smith drops Let's Kill Hitler hints

This year's San Diego Comic-Con featured an appearance from Karen Gillan and Matt Smith.

Matt Smith revealed that the next episode, Let's Kill Hitler, is his favourite episode. "
The next episode... 'Let's Kill Hitler,'" says Smith. "[Creator] Steven [Moffat] is in fine form, and there's a great monster, which is important."

As to River's identity: "I find out quite sort of late, he says, "but I thought it was good payoff... Going into the next part of the season, there's some real good River stuff and some real good River/Doctor
stuff."

And as to where he'd go if he had a TARDIS:

"I'd go to Atlantis and see if that's just... going down," he says, "And I would go and visit the dinosaurs but I would pick up Frank Sinatra along the way."