Josh and Danny know that their day is going to be a nightmare when their mum invites Tarquin round from next door. But they have no idea exactly how deadly the day will become until they are accidentally turned into ants. Where's Petty Potts - their friend and mad scientist - when the twins need her to SWITCH them back?

Armed with his magnifying glass, Tarquin can't wait to roast some insects. Danny and Josh may each have six legs but will they be able to get away in time?

Petty Potts's diary entry:
I have to warn Josh and Danny about the spies. I don't think they believed me. I might have to show them some evidence of my life before, when I worked with Victor Crouch in the government's secret underground labs. And I should probably show them his photograph. They need to be on their guard now.

They may only be children, but that wouldn't stop Victor if he ever found out what they knew. That wouldn't stop him at all . . .

Illustrated by: Ross Collins