The Avengers #47 (1967)

In Avengers #47, things get serious as we see Captain America leaving the team, leaving the rest of the Avengers in a state of shock. But it's not just Cap's departure that's got everyone on edge. Magneto is back on Earth, and he's intent on capturing the Scarlet Witch and Quicksilver, who he believes belong on his team of mutants. And as if that wasn't enough, the Toad and Magneto have teamed up to form the core of the Brotherhood of Evil Mutants, which means they're stronger than ever before. They even manage to sneakily use some tech from Dane Whitman, luring the Scarlet Witch and Quicksilver right into their clutches. Meanwhile, Hawkeye and Black Widow are having some issues, and Hercules is back to an empty Olympus. It's all going down in Avengers #47, and you won't want to miss a single panel.