Contains all 4 books in the interlinked Zac Power Extreme Mission Super Series! When Zac Power's grandpa drags him on a new mission in the middle of the night, Zac is pumped. They're racing to find the four parts of a powerful gadget called IRIS. But Grandpa won't say what IRIS does, or why it's been broken up. The only thing Zac knows is that this time, the threat is bigger than to just GIB. If they don't find IRIS before their enemies do, the whole world will be in danger...