Mark Ruffalo is trying not to spill about Avengers: Endgame!

The 51-year-old actor made an appearance on The Tonight Show Starring Jimmy Fallon on Wednesday (March 13).

PHOTOS: Check out the latest pics of Mark Ruffalo

During Mark‘s appearance, Jimmy hooks up the notorious movie plot spoiler to a lie detector to get the truth about Avengers: Endgame. Will he spill details about the upcoming movie?

In the movie, out on April 26, after the devastating events of Avengers: Infinity War, the universe is in ruins. With the help of remaining allies, the Avengers assemble once more in order to undo Thanos’ actions and restore order to the universe.

Watch below!