Originally posted by MonAmos
...or maybe the mutant massacre. that would still involve Gambit and Sinister, Angel, Marrow (played by Dakota Fanning). Beast could have retreated to the morlock tunnels after his experiment, but after encountering Xavier, he joins the staff at the institute. there could be an indirect plot involving training in the danger room and using those skills during battle as the X-men and the younger mutants encounter the mutant underworld.(it'd be difficult to fit in the Phoenix, but i'm hoping they sign on for more sequels to explain that story later.)
Marrow by Dakota?
You're lucky I adore the girl's acting.