It's the bicentennial issue of Earth's Mightiest Heroes! However, the mood at Avengers Mansion is bittersweet as Ms. Marvel gives birth to a healthy baby boy after a bizarre three-day pregnancy. Something very strange has happened to Carol Danvers, but Dr. Donald Blake and Hank Pym cannot determine what. Something else rather strange is also happening to New York City...prehistoric dinosaurs, medieval knights, and alien spaceships! Where in the world, or perhaps, when in the world did they come from?!? One avenger has a strong suspicion... the now full-grown son of Carol Danvers! When Hawkeye confronts "Marcus" and his mysterious machine, the truth is revealed! Will the truth bring a happy ending to everyone involved...or just appear to? First and final appearance of Marcus Immortus. Flashback cameo by Immortus. Avengers Lineup: Beast, Captain America, Iron Man, Hawkeye, Jocasta, Ms. Marvel, Scarlet Witch, Thor, Vision, Wasp, Wonder Man, and Yellowjacket. Notes: Avengers 200 generated considerable controversy concerning the circumstances of Ms. Marvel's unwilling pregnancy.