Ax and the Animorphs are confused - and worried. The Yeerks have taken over an animal-testing and meat-processing plant. Are they trying to poison human food? It doesn't make sense - the Yeerks need their host-bodies alive and healthy. The factory and lab must be connected - what are they testing? And what - or who - are they using for lab-rats...There's only one way to find out what's going on. The Animorphs have to go in. Which means disguise-morphs. Which means that somebody has to morph a cow, and then walk right into a slaughterhouse...