Avengers (1963 1st Series) #263

Return of Jean Grey: Part 1 of 3 - "What Lurks Below?" X-Factor tie-in. Script by Roger Stern. Art by John Buscema (breakdowns) and Tom Palmer (finishes). Cover by John Buscema and Tom Palmer.

While attempting to escape from the police, the Enclave's charter jet skids off the runway and crashes into Jamaica Bay! The plane erupts into a giant fireball, but one piece of cargo safely sinks to the bottom of the bay. Captain Marvel is the first avenger on the scene and finds a strange energy cocoon half-buried in the bay floor...