Two brothers, one serum, and a world of trouble!
In 'Ant Attack', the twins are horrified when they are accidentally turned into ants: can they escape before terrible Tarquin roasts them under his magnifying glass?
'Crane Fly Crash' finds Josh and Danny going on a rescue mission to save their annoying big sister, Jenny, after she accidentally uses the S.W.I.T.C.H spray and turns into a crane fly!
And in 'Beetle Blast', a chocolate muffin laced with S.W.I.T.C.H. spray sees them beetling about in a pond, breathing underwater, and creating the most almighty stench to scare off predators....