Captain America (1968 series) #121

Professor Silas X. Cragg has a mad, fanatical obsession with Captain America, seeing him everywhere he looks. After researching all that is known of Cap’s origin at the library, he proceeds with his plan to destroy the Star-Spangled Avenger. Cragg has devised a serum similar to the one that gave Cap his powers and plans to use it on a powerful man, who will then be stronger and deadlier than Cap and able to destroy him. In the Bowery he spies a hulking giant of a man whom he interests in his scheme and takes his subject home. The treatment turns the huge derelict into the powerful Man-Brute, ready and able to kill his costumed quarry….

Later, Cragg visits Avengers HQ and tells the heroes that he is seeking Captain America to perform in a charity show at an orphanage. The Avengers pass the invitation along to Steve and he arrives at the site, only to be attacked immediately by the Man-Brute. Children and reporters believe the fight is part of the show but Cap manages to steer the kids to safety. Cap uses his agility to dodge his muscular foe but the room is too small to allow for his full movement. An orphan named Robert rushes to Cap’s aid, hitting at the Man-Brute, and, to Cap’s surprise, the hulking villain turns and runs away, leaving Cap with the orphans. The Man-Brute returns to Cragg’s home where he turns on his creator, lauding Cap as the bravest man he’s ever known, and describing the brave boy who tried to defend his hero—revealing to Cragg that the spunky kid was his own son! Man-Brute shoves Cragg into the machinery and the madman is electrocuted. The powerful giant vows never to use his deadly strength again….

Later, Cap tells Nick Fury how he finally located Cragg’s lair and found the scientist dead and the Man-Brute missing. That evening, Cap goes for a walk in the Bowery meditating on his loneliness and deciding he’ll never see the Man-Brute again—unaware he has just walked past his former enemy….