Playaway Digital Audio.

Their magic tree house takes Annie and Jack to Pompeii just as Vesuvius is about to erupt, and they must find a Roman scroll before everything is covered with burning ash.

Their magic tree house takes Jack and Annie to the Arctic, where a polar bear leads them onto very thin ice.

"Jack and Annie are about to meet the fiercest warriors of all--the soldiers of the ancient Roman legion! When the magic tree house whisks them back to a ROman army camp, they learn their mission: Be like warriors. That is easier said than done--Roman soldiers are the best fighters in the world! When Jack and Annie find themselves in the wrong place at the wrong time, they're in big trouble. Who will save Jack and Annie?"--Book jacket.

"When the magic tree house whisks Jack and Annie back in time, they land in the tallest tree in Yosemite, California where they join nature conservationist, John Muir, and US President Teddy Roosevelt on a historic trip through the woods"--

Using their magic tree house, Jack and Annie travel back to the time of the American Revolution and help General George Washington during his famous crossing of the Delaware River.

"The magic tree house whisks Jack and Annie away to Greenland where they discover they've traveled back in time to meet Lief Erikson"--

The magic tree house is back with a message from Morgan le Fay telling Jack and Annie to seek out "The Gray Ghost" and listen to her story, and immediately they are whisked away to Nepal where they meet Tenzin, a climber who has recently lost his family, and who takes them up the mountain to meet a snow leopard and renew himself.