A hidden lab.A grisly discovery.An eerie swamp.Can Sadie and Newt uncover the secret of the swamp before it's too late?Sadie is not impressed by her latest school holiday destination - a cabin in a mud-infested swamp in the middle of nowhere aka "Sanctuary DeVolfe".Sadie meets Newt, the nerdy kid staying in the cabin next door, and the pair go off exploring the murky depths of the stinky, slimy swamp. But something odd is going on at the Sanctuary. And what is the mysterious and cranky Professor DeVolfe trying to hide?When her annoying brother Charlie gets sick with a weird virus and then goes missing, Sadie and Newt set out on a mission to find him but soon make a grisly discovery at the Professor's hidden lab.Will they find Charlie?And what secrets are hiding in the swamp?