The Scarlet Witch has a breakdown. Her son reminds her of what she's lost — her children, her sanity, her place in the world. She whispers three words: 'No more mutants.' Reality reshapes. In an instant, the mutant population drops from millions to 198. House of M collects the complete Brian Michael Bendis-written event that permanently altered the Marvel Universe and set the X-Men's direction for nearly a decade. The complete M-Day story in one volume.