time travel

Huge meat-eating lizards and flying reptiles have swooped into Spooksville through a doorway to the past, and Adam and his friends must hurry to find a way to close the portal before the entire town becomes a dinosaur feeding ground.

T?o sends Elena, Jorge, and Marcus to a small town in Iowa in 1983. This sounds like a boring adventure, until they learn that they're going to one of the first video game competitions.

Elena, Marcus, and Fiona time travel to 1972 Minneapolis-Saint Paul, where they attend the State Fair while seeking a werewolf that is associated with the Guthrie Theater.

The cradle of civilization is being drained of life--by a vampire! Amy, Elena, and Marcus use T?o's time machine to venture back to ancient Mesopotamia, where a vampire is plaguing the Mesopotamian people and their crops. Can the team solve the mystery of the damaged crops and keep the people--and the vampire--safe? This graphic novel includes monster profiles and survival tips as well as in-depth content on the social structure, government, and fashion of the Mesopotamian civilization. Backmatter includes an activity page and character information.

Elena, Jorge, and Marcus must brave the Chicago winter in search of a vampire. In a bleak, post-Depression city, the children must not only find this creature of the night.

Elena, Amy, and Fiona band together for an exciting adventure. T?o sends them back to ancient Rome, where a witch is being accused of taking the form of an evil creature. Is this witch real? Is she dangerous? Or is she in danger? Join the girls on a breakneck adventure through the city of Rome in all its glory--from the Colosseum to the Market of Trajan. This graphic novel includes monster profiles and survival tips as well as in-depth content on the social structure, government, and fashion of ancient Rome. Backmatter includes an activity page and character information.

The kraken is the biggest monster in the sea. And in the 1950s, it seems to be headed straight for Boston!.

Elena, Fiona, and Marcus travel back in time to Mexico during the reign of the Aztec empire. There have been sightings of a powerful mermaid named Tlanchana, thought to be causing a devastating drought. The monster hunters learn about Aztec festivals, music, and culture on the streets of Tenochtitlan. Follow the team as they race against the clock to return a stolen crown to Tlanchana, known for being more wicked than sweet. Will she end the drought and remain hidden from the human world? This graphic novel includes monster profiles and survival tips as well as in-depth content on the social structure, government, and fashion of the Aztec Empire. Backmatter includes an activity page and character information.

Jorge, Elena, and Amy need to find a poltergeist before it reveals itself to the world. The only catch? It's in Seattle--and it's in the 1990s.

Jorge, Marcus, and Amy must find the missing sphinx! T?o sends them on their way to ancient Egypt. Before the famous statue was built, he tells them, a real sphinx guarded the pyramids in Giza. The monster hunters travel back in time to locate the sphinx, exploring ancient Egyptian culture along the way. Can they help the sphinx stay out of trouble with the cruel pharaoh? This graphic novel includes monster profiles and survival tips as well as in-depth content on the social structure, government, and fashion of ancient Egypt. Backmatter includes an activity page and character information.