In this series, The Magus, the purged, evil side of Adam Warlock believed to have been dead, has returned in order to collect the Infinity Gems and recreate the Infinity Gauntlet itself. He sent evil doppelgangers of Marvel’s superheroes to attack and usurp the originals. Thanos, exiled since his defeat during the Infinity Gauntlet event, learned of the Magus’ plans and set out to aid Adam Warlock and the heroes in defending the universe.
In 2004 Thanos received an eponymous title that ran for 12 issues. After defeating the Hunger, Thanos went to the frontline and gave himself up to the Omega Corps. After a panicked action from the corps they send him to the Kyln. On his way he killed a Skrull agent to give them a reason to imprisoned him. On Kyln, a priest told him about the prison while Thanos is watching the Crunch. When the Priest left, Death appeared and talked to him, telling him She loves him in her way, and that he hadn’t given her anything that she didn’t already have.
The storyline is the culmination of events from Silver Surfer vol. 3, #34 (Feb. 1990) and the two-issue miniseries The Thanos Quest (Sept.- Oct. 1990).
Thanos mounts the six Infinity Gems (collected in the Thanos Quest limited series) on his left glove to form the titular Infinity Gauntlet. Each Gem grants its bearer complete mastery over one aspect of the multiverse: Time, Space, Mind, Soul, Reality, and Power. Now all-powerful and desperate to win the affections of Death, Thanos decides to offer the entity a gift of love by completing a task she had given him, erasing half the sentient life in the universe (including most of the X-Men, Daredevil, and the Fantastic Four), quite literally with a snap of his fingers.
Additional plotlines not addressed in the main story were featured in other books published during the same time period.
The storyline led to two sequel miniseries, Infinity War and Infinity Crusade. All three series were the core of a company-wide crossover story.