Iron Man: House of M #1

In "Father's Day," Tony Stark enters the brutal Sapien Death Match, where he bests Johnny Storm only to be defeated by his father, Howard. Back at his company, he fires researcher Hank Pym after uncovering Pym’s illegal work mapping the mutant genome. When Pym vanishes with all his research, Tony suits up in his new Iron Man armor and tracks him to a human resistance meeting—only to find himself fighting Sentinels that have followed him, leading to a shocking confrontation with the man controlling them. Written by Greg Pak and illustrated by Pat Lee, with cover art by Pat Lee, this 2005 issue delivers high-stakes action and a personal twist in the heart of the House of M universe.