Generation X, Vol. 1 #38A (1998)

Mystery Train
Banshee, Husk and Penance are rocketing along on an interdimensional train looking for Synch when they are reunited with Chamber and Jubilee. The team takes the train to the Citadel of the Universal Amalgamator where M-Plate is trying to force Synch to use his mutant powers to activate the machine. Once Synch's friends arrive, M-Plate uses them as pawns in her game. Just as Synch is on the point of doing the deed to save his friends, the mutant rat, Dirt Nap, leaps down and swallows M-Plate.
Release Date: 1998