It's five years later and the SENTINELS are back. They've moved operations from the Texas desert to the tropical island of New Atlantis. They're up against The Hastings Foundation as it strives to harvest the cryospore, a new pollution-free energy source that is explosively unstable outside the confines of its icy home. At the same time, a shadowy organization called The Swarm works tirelessly to bring about a new reckoning. The SENTINELS must face down their former leader, Captain Pierce, who now has superhuman abilities of his own and leads The Tribe, a group of rogue Mods. Can the SENTINELS use their superpowers to survive kidnappings, betrayals, uneasy alliances, dramas, and traumas to once again save the world and be the heroes they were meant to be?