Nathan Fillion says that he may have a cameo in the upcoming Marvel film Guardians of the Galaxy.

This past weekend, Wizard World Comic Con descended on St. Louis and boasted big stars such as Doctor Who’s Matt Smith and Karen Gillan, the original Batman’s Adam West and Burt Ward, Lord of the Rings’ Sean Astin, and numerous others.

In addition, the con held a mini Firefly reunion where Nathan Fillion, Adam Baldwin, and Alan Tudyk sat down together for a panel. The three reminisced about Firefly, jokes they played on set, and more. The crowd was riled up by general hilarity.

Toward the end of the panel, St. Louis fans were treated to a huge surprise. A fan asked Fillion if he was wanting to get a part in Guardians of the Galaxy.

The actor replied, “Wanting to get a part… or maybe did.” He paused as the crowd went crazy then continued, “I’m just saying maybe. Maybe you’ll be surprised. Maybe. Check the credits.”

For proof check out this video of the Firefly panel. The Guardians of the Galaxy question occurs around 38 minutes, 30 seconds in.

So there you have it, Marvel fans. Maybe Fillion wasn’t too busy filming Castle to drop in on Guardians of the Galaxy. Where do you think he might appear in the film? Hopefully we won’t have to wait until August 1, 2014 to find out for sure!