In tales that ushered in the new millennium, Superman returns to Smallville and teams up with Superboy! Plus, The Joker and Harley Quinn invade Metropolis! And in �Critical Condition,� Superman must search for a missing Lois Lane while a mystery illness threatens his life! Collects Superman #155-159, Adventures of Superman #577-581, Action Comics #764-768, and Superman: The Man of Steel #99-103.