Books 1-8 Dinosaurs Before Dark, The Knight at Dawn, Mummies in the Morning, Pirates Past Noon, Night of the Ninjas, Afternoon on the Amazon, Sunset of the Sabertooth, Midnight on the Moon
In their magic treehouse, Jack and Annie are again transported to King Arthur's realm, where invisible beings, giant ravens, and mistaken magic spells have a duke's castle in an uproar on Halloween night.
The magic tree house whisks Jack and Annie to Washington D.C. in the 1860s where they meet Abraham Lincoln and collect a feather that will help break a magic spell.
As a thank-you from Merlin and Morgan, Jack and Annie are sent on what should be a vacation at a luxurious resort in Cozumel, Mexico, but is, by mistake, an adventure with ancient Mayans, instead.