Ultimate X-Men, Vol. 1 #4

In the wake of Beast's nearly fatal accident, Cyclops has gone into a bit of a depression. When Wolverine starts to get closer to Jean, it drives Cyclops away. Even though the Professor has halted the Sentinel program and is starting to open negotiations, Cyclops leaves to join Magneto and his Brotherhood.

Story Arc: Tomorrow People

Release Date: Apr 04, 2001