Collects the Weapon X stories from Marvel Comics Presents (Vol 1) #72-84.
The project was named Experiment X and it was revealed that it was responsible for bonding the adamantium to Wolverine's skeleton, making it unbreakable, and for subjecting him to brainwashing in order to bring out his most basic murderous instincts in order to transform him into the perfect assassin. The scientists christened their new killing machine "Weapon X".