It was a pretty bold idea to bring back the original X-Men team considering all that had happened since they disbanded. The Beast now sporting blue fur, Cyclops was married with a young child, Ice-Man and Angel both had brief stints with The Champions and as if that wasn't enough Jean Grey (Marvel Girl/Phoenix) was dead.
The way Jean was resurrected may have seemed contrived at the time but it was a brave decision and the loss of her ESP power paved the way for some great story-lines especially those involving Scott's relationships with Jean and the break-up of his marriage to Maddy.
Secretly funded by Angel's family wealth the team have a high profile public image as mutant hunters, under that cover they track down mutants to try and teach them to control their powers so they can live amongst "normal" people. The team soon grows to include Rusty Collins, Artie Maddicks and Skids and there are a whole host of mutant background characters some memorable others far less so.
The highlights of this volume include the first appearance of Apocalypse and his first 3 Horsemen; Mystique and The Brotherhood of Evil Mutants now working for the US Government to track down mutants as "Freedom Force"; the start of the Mutant massacre as the Marauders, including Sabretooth and Arclight, launch a murderous attack on the Morlocks underground base (guest-starring Thor and Power Pack) and the return of The Sentinel Master Mold.
I have to say that some of the artwork in later issues looks pretty awful in black & white but the last story here (#16) more than makes up for that with a moving story line, well worth reading.