We start with the X-Men taking a trip to New York, and explaining how they hide their various mutant traits. They hide in plain sight, disguising their features.
But a new robot army has been designed to hunt them down.
Thus, the second “signature enemy” for the team is introduced: The Sentinels. The mutant-hunting Sentinels in many ways capture the heart of the X-Men concept: Human fears of Homo Superior made manifest in what is essentially an ethnic cleansing robot.
Bolivar Trask is the architect.
He gets good press.
But as the robots attack and capture the X-Men, they begin to inexplicably stop operating.
The robots themselves don’t know what is going on.
It turns out, they are under the thrall of Master Mold, an even bigger Sentinel whose job is to make and rule other Sentinels. He orders them to turn on Trask.
Trask is taken to meet Master Mold.
The X-Men rescue Trask, of course. But not before they also get captured.
The teens are put in a clear box–a precursor to the omnipresent clear tubes that Marvel heroes will find themselves captured and stored in by countless villains in the decades to come.
While captured, under hypnosis, Beast tells his origin.
Of course there are sports.
Trask has his come-to-Jesus moment as X-Men fight their way through Master Mold’s fortress to rescue their captive members.
And Trask is killed.
That shadowy figure is Magneto. He returns from his adventure in space with The Stranger next issue.