"Ultimately, when we were shooting the train station scene -- this is actually fun -- all the extras are staff from 'How I Met Your Mother.' They're all there. It was really fun. I kind of felt bad for [SPOILER] because it was really like Jesus has risen when she showed up on the set -- the whole crew was like 'Here she is, the women we've been waiting for for 10 years!' And she's like, 'I'm just an actor.'"