Uncanny X-Men (1981) 316-A

"Generation Next, Part 1: Encounter"
Continues in X-Men (Vol 2) #36.

The Phalanx has returned with a new mission, find and destroy young mutants known as Generation Next. Meanwhile, Banshee has returned to the mansion but something is wrong with how the X-Men are acting, leading Banshee to do some old fashioned investigating as he learns that the Phalanx have taken over. He is not alone as Sabretooth, Emma and Jubilee are still in the mansion as Banshee must gather his forces and protect Charles' files on the next generation of mutants from the Phalanx.

First appearance of M (Monet St. Croix).