At the start of summer break, two familiar faces confront Atlas in Malcolm's lab, and entrust him with a relic from his family's past, and an urgent request: Find the Oracle! With the help of his siblings, Lilou and Nico, and some unexpected guests, Atlas returns to the Multiverse to find his friend Mia and save the Alliance from a looming invasion. With P.O.R.T.A.L. hot on their heels, the adventurers travel to familiar and new realms, where they encounter new and menacing foes - and seek to put an end to Craum's evil plans. Can Atlas find the Oracle, save his friend, and stop the invasion before it's too late?