So, that's Black Widow, Maria Hill, Scarlet Witch, and...who could be the fourth? It's an intriguing detail, and with Carol Danvers/Ms. Marvel/Captain Marvel rumoured to make her big screen debut in, could she be the fourth? Well, when HeyUGuys asked writer and director Joss Whedon exactly that, he remained coy, but did say that the character is one of his favourites. Who do you guys think it could be? Be sure to check out the interview in full above, and then head on over to the site for more of Q&A's with the cast of