Captain America was then formally reintroduced in "The Avengers" #4 (March 1964), which explained that in the final days of World War II, he had fallen from an experimental drone plane into the North Atlantic Ocean and spent decades frozen in a block of ice in a state of suspended animation. The hero found a new generation of readers as leader of that superhero team. Following the success of other Marvel characters introduced during the 1960s, Captain America was recast as a hero "haunted by past memories, and trying to adapt to 1960s society".