It seems like a regular field trip to a natural history museum—until Zack gets locked inside for the night and discovers what really goes on in those display cases when no one is watching. A tribe of curious Neanderthals, rampaging woolly mammoths, prehistoric food shortages . . . it’s just another wild adventure for Zack!

After a class trip to see the Neanderthals, Zach gets locked into the Rosencrantz Museum on the night of the new moon, the one time of the month when the prehistoric people and animals in the exhibits come to life.

The Zack Files #25.

When Zack is given the chance to swim with dolphins on a trip to Florida, he dives right in. But before long, Zack is surprised to find that the dolphins are trying to tell him something ? and even more surprised that he can understand and talk to them! There's definitely something fishy going on here! Could it be genuine animal communication? And can Zack and his new friends get their signals straight and salvage an old sunken ship filled with treasure?

Zack's new substitute teacher seems kind of odd. And she is rather hairy. And get this, her name is Mrs. Wolfowitz! But is she really a werewolf? Or just one very weird lady who happens to like the taste of homework papers? Read on to find out!

Uh-oh! Thanks to a heaping helping of a new dietetic sugar substitute, Zack shrinks down to the size of a bug. It's not all that bad--until he discovers an army of ants who are building an ant pyramid for their despotic pharaoh-queen!

Late one night when Zack hears strains of "Heartbreak Hotel" coming from the fridge, he discovers the possibility that Elvis lives on...as a turnip! Talk about getting back to musical roots!