Uncanny X-Men #9
"Enter, The Avengers"
Written by Stan Lee
Drawn by Jack Kirby
One of the original "meet-up and beat-up" crossovers of yesteryear as the X-Men go to meet up with Xavier and run into the Avengers. The two groups feel the need to tustle, each thinking that the other are villians only to back off when they realize the truth: that they are on the same side. Unlike most of these meetings those, the Avengers go their own way rather than teaming up with the X-Men.
It's good to see Xavier on his own out in the field but why in the name of God does he allow Lucifer to go free? This is the man who took the use of his legs from him and his continued freedom is a threat to humankind. I know Xavier wants to be the bigger man but honestly not even prision?

