David Tennant and Billie Piper took part in a Q&A panel at the Wizard World Comic Con in St Louis yesterday,
Here's a few highlights from their chat...
David Tennant & Billie Piper take to the stage for their panel at Wizard World St. Louis 
"There's something quite hard to beat about playing the Doctor." - David Tennant 
"I was jealous Matt Smith got to hang out of the TARDIS for the 50th, it was cool!" - David Tennant 
"When there's a love story involved, it becomes more accessible to everyone" - Billie Piper
"You're just hyper. You run before takes" - Billie Piper
"I run like Phoebe from Friends!" - David Tennant
"For me, I'd want to be in Genesis of the Daleks. I have vivid memories" - David Tennant
"The daleks are exciting to be on set with because everything echoes and booms and the lights flash " - David Tennant
David on his favourite line ever "I cant say it cause it has swear words"