This book collects the 1967 and 1968 comics of the X-Men, issues #32 through 42. They fight the Juggernaut, Tyrannus and the Mole Man, Spider-Man, Mekano, Factor 3, Frankenstein's Monster, and Grotesk. They get new costumes, and their leader, Professor X dies (or at least somebody playing him dies, as will be revealed almost two years later). I had most of these issues as a kid, and several remain beloved - most of all #36, the one where they fight Mekano, who is a lame super-villain, but all the rest of the story, showing the X-Men trying desperately to raise money in order to get to Europe where Factor 3 is holding Prof. X a prisoner, is terrific. I love the attempt to become construction workers, only to be foiled by a lack of union cards.
These comics are not universally beloved by fans, but they meant a lot to me at the time, and they have their good points. Some very nice art by Dan Adkins and Don Heck in some of them, some fun side-bar scenarios that Roy Thomas came up with, the sense of mystery around Factor 3 that didn't pan out to a strong conclusion, the growth of characterization between Cyclops and Marvel Girl, the amusement value of the River Lethe, and a fun use of Spider-Man - all this made this re-read more than a pleasure.