"Where did the tree house come from? Before Jack and Annie can find out, the mysterious tree house whisks them to the prehistoric past. Now they have to figure out how to get home. Can they do it before dark ... or will they become a dinosaur's dinner?" --

Molly Moon's hypnotic eyes give her the power to stop the world and travel through time. Now Molly makes a stunning new discovery - she's a mind reader! But can her incredible talents help to rescue her lost twin from future? And will Molly be a match for the maniacal Princess Fang and her crazy mind machine?

The mysterious box that Ranger the golden retriever found in the garden transports him back to first century Rome, where he must rescue Marcus, a young servant boy, and Quintus, a volunteer gladiator, from the brutal world of the Colosseum.

Sent back in time to 79 AD, on a mission to photograph the eruption of Mount Vesuvius, the Flashback Four race to get their picture.

Dak, Sera, and Riq return to the United States and walk right into a deadly trap. The year is 1850 and the nation is divided over the issue of slavery. In these dark days, the Underground Railroad provides a light of hope, helping runaway slaves escape to freedom. But the SQ has taken control of the Underground Railroad from within. Now Dak and Sera are left wondering who to trust...while Riq risks everything to save the life of a young boy.

Jack and Annie visit the Paris World's Fair of 1889 in an effort to protect four scientific pioneers from an evil sorcerer.

Which door would you go through to save the world?

David, Xander, and Toria King never know what new adventures—and dangers—await them beyond the mysterious portals hidden on the top floor of their new house. They have battled gladiators and the German army, dodged soldiers on both sides of the Civil War, and barely escaped a fierce attack in their own home.

Still they are no closer to finding their mother,

...

"In The Secret Explorers and the Tomb Robbers, Gustavo (history expert) and Kiki (engineering expert) are sent the mission of stopping the Cairo Museum from closing down. They travel back in time to Ancient Egypt and are soon drawn into a tense, thrilling adventure that involves breaking into pyramids, learning ancient Egyptian hieroglyphics, and stopping thieves hoping to rob all the treasure from the Pharaoh's tomb"--Amazon.com.

This time the mysterious box transports the golden retriever Ranger back to the shipyards of Belfast in 1912, where a ship is being prepared for her maiden voyage, and when he saves young Patrick Murphy from being crushed by falling boards, Ranger expects to be transported home; when he is not, he knows that somehow his job is not finished--but then, Ranger has never heard of the Titanic, and knows nothing of the fate that awaits Patrick, and all...