This is the first appearance of Mesmero and Lorna Dane (Polaris).
Angel goes back to the Xavier mansion and suddenly Cerebro starts to beep very louder. He warns Jean and she contacts the others X-Men. Meanwhile, in San Francisco, a strange group is commanded by Mesmero, in name of his dead master Magneto. Mesmero use his powers and a machine to awake all latent mutants and call them to join his army. One of these new mutants is Lorna Dane, and as she is hypnotized walking in a street, Iceman save her from a car and take her to his hotel room. So, while Beast is finishing a Portable Cerebro, the X-Men fight Mesmero's mutant squad and Angel get injured.
When Beast finishes his machine, he discovers that the young Lorna Dane is also a mutant. The X-Men left Iceman taking care of Lorna at the apartment and go look for Mesmero, but he find them first and capture Lorna and Iceman.
Second Story: "A Beast is born" - the story about how Beast got his powers. Beast's father used to work in a nuclear factory, and one day he got exposed to the radiation to save his fellows and the whole city. This exposure altered his DNA and his son become a mutant, the Beast.