Avengers #55

1st full appearance of Ultron

3rd appearance of Black Knight (Dane Whitman)

"Mayhem Over Manhattan!"

The Avengers are held captive, and it is shown that the Crimson Cowl isn't the Edwin Jarvis at all, but the robot Ultron-5. Jarvis is supposedly killed, but he escapes and finds the Black Knight, who helps him. The Black Knight then attacks the Masters of Evil and frees the Avengers. Together they defeat the Masters. Although Ultron and Whirlwind escape, the rest are imprisoned. The Avengers decide to give Jarvis a second chance.