Fifth-grader Winnie, with notes from her friends, writes of turning her treehouse into an embassy after her newly-divorced parents become unreasonable, where she is joined by nine others with complaints.

Andy and Terry's amazing 65-Storey treehouse now has a petgrooming salon, a birthday room where it's always your birthday (even when it's not), a room full of exploding eyeballs, a lollipop shop, a quicksand pit, an ant farm, a time machine and Tree-NN: a 24-hour-a-day TV news centre keeping you up to date with all the latest treehouse news, current events and gossip. Well, what are you waiting for? Come on up!

Jack and Annie go back in time to New York City, during one of the darkest periods in the city's history--the Great Depression. Even worse, the city is in the grip of a terrible snowstorm. To stop the blizzard, Jack and Annie must save the unicorn made famous in the Cloister's medieval tapestries. But will that be enough to help a city that faces so many troubles?