God of War: Ghost of Sparta, the follow-up to the excellent handheld Chains of Olympus, takes place between the original God of War and God of War II. Kratos may be at the top, but he's still searching for answers about his fate. Ghost of Sparta begins with an angry Kratos and, well, will end with one too. The game's story will expand on Kratos's backstory and show players why he's so pissed at the start of the second game (not that Kratos even needed a reason).
His quest takes him to Atlantis, though the journey is cut short when Kratos's fleet is attacked by a group of sea creatures led by Scylla, a beast with multiple tentacles protruding from its chest.