There are roughly 10,000 characters in Marvel's superhero smorgasbord "Avengers: Age of Ultron," opening May 1st nationwide. The sequel to the $1 billion+ grossing "Avengers" sees the super team facing down the evil robot Ultron and his ever-growing army of robotic doppelgängers. But if you haven't kept up with the various superhero standalone movies in the Marvel Cinematic Universe, we wanted to make sure you knew who was who going into "Avengers: Age of Ultron." So behold, our handy guide.

This should bring you up to speed on who is who and what they've been up to, in the events leading up to "Age of Ultron" (and in "Age of Ultron" itself). There are minor spoilers, so if you're squeamish, beware. But, ultimately, this is supposed to be a tool to educate and entertain and remind you who, exactly, is punching whom. Excelsior!