An evil ventriloquist's dummy is terrorizing the O'Dell household, and Dan and Trina are getting blamed for Slappy's nasty tricks. When dummies speak everybody listens! Trina O'Dell's dad used to have a ventriloquist act. That's why he has all those dummies in the attic. He calls it his Dummy Museum. There's a dummy with freckles. And one with a sneer just like Rocky. Trina and her brother, Dan, think the dummies are pretty cool. But now there are voices in the attic. And dummies keep showing up in the strangest places. No way those dummies could be alive! Right?