'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…' (Publisher's blurb)
'The second piece of the evil IRIS is hidden deep in a dangerous forest. Zac has to battle an army of androids, but there are more surprises in store.' (Publisher's blurb)
'Zac's whole family has been recruited to sneak into the City of Snow. They have to save the third piece of IRIS - but it's hidden in the crown of the king himself! And when Zac's family is taken hostage, he's faced with the toughest decision of his spy career. Will he stay and fight for his family, or go and save the world from BIG and IRIS?' (Publisher's blurb)
'The final piece of IRIS is hidden deep in the ocean, protected by an underwater minefield. Zac is running out of time to rescue his family and take IRIS before his enemies do. The whole world is at stake, and it all comes down to Zac...' (Publisher's blurb)