HIMYM - Jason Segel and Alyson Hannigan discuss the final scene in "Bad News"

In my opinion, this proves what amazing actors Jason and Aly really are.

Segel revealed there was a lot of work by the HIMYM producers to keep this plot turn under wraps, explaining, "In the script we received, the last scene was, 'Marshall, I'm pregnant.' And then they told us on the day, 'No, that's not what's happening.' And they gave us the alternate pages."

Both Segel and Alyson Hannigan spoke about Segel's decision to not know what Hannigan's exact lines were in that scene. As Segel put it, "I didn't want to know what she was going to say to me when she got out of that cab." Hannigan recalled asking, "'Jason are, you sure?' I was like, 'I'm going to take some pauses and okay, the last word [for your cue] is 'it.'' I was like, 'I don't say 'it' any other time.'"

Said Segel, "I had no idea what [Hannigan] was going to say to me. I knew the overall premise, but she came out and she was already crying and it was so heartbreaking and it made acting very easy. All I had to do was react in that scene. I didn't have to dig very deep."

Amazingly, only one take of that powerful scene was filmed. Hannigan recalled asking the director and producers, "'Are you sure? We should probably do it again!' But they were like, 'It's perfect!'"

Source: IGN