Hayley Atwell, who played Peggy Carter in the Marvel Phase One adventure Captain America: The First Avenger, teased that Marvel may be debuting a short film featuring Peggy Carter at Comic-Con 2013.

"There's been an online campaign for Peggy to be featured. People really liked her. So Marvel have made sure that as part of Comic-Con there will be a little kind of snapshot as to what Peggy's actually really capable of, which was finished here and which was great fun. Hopefully, it will lead to other things."

There is speculation that this "snapshot" could be a short film that bridges Captain America: The First Avenger and the upcoming sequel Captain America: The Winter Soldier. If that is the case, this may be the latest in the Marvel One-Shot series of short films. The most recent short, Item 47, debuted on the Marvel's The Avengers Blu-ray and DVD release.

The actress also confirmed a report from February that she is returning for Captain America: The Winter Soldier.

"They're so tight, the Marvel family, and private. I can say that I am involved in some way in the second one. Just know that it's not me being cryptic, it's Marvel. They can just as easily kill me off if I threaten to tell the story before it's time. They're keeping it all under wraps."

She also spoke about the possibility of revisiting Peggy Carter in a movie or TV spin-off.

"I'd revisit Peggy again. She's pretty uptight. I'd like to, if I get a spin-off, definitely add a bit of humor in there. She's very British. Very uptight. Let's hope if she gets a spin-off it's modern day, so she can relax a little bit, let go of the uniform."