Knight at Dawn (Magic Tree House, Book 2) (by Mary Pope Osborne)

Here, they witness a feast in the Great Hall. When they are questioned, "Who art thou?" the two run for cover, finding themselves caught in a room full of armor. Three unsavory guards corner them in the dungeon, until Annie pretends her flashlight is a magic wand and stuns them.

A trapdoor provides easy escape into the moat filled with crocodiles, when along comes a knight on horseback, delivering them to safety. At home, Jack notices an M on the bookmark, and concludes that the same person who dropped the coin in the first adventure also owns the books and is responsible for the magic in the tree house.

The Middle Ages fascinate kids, but this is one flying tree house adventure with a ho-hum plot that never really gets off the ground. Jack does his usual observing, and Annie her characteristic disappearing act, but witnessing the Middle Ages from doorways and through windows is not enough.

Still, kids will find a dash of humor to enjoy, such as eating peacocks, the silly names of the three guardsmen -- Squinty, Mustache, and Red (who ask them if they are "Spies? Foreigners? Egyptians? Romans? [or] Persians?") -- not to mention the moment when the two central characters discover the meaning of precipice and tumble into a moat.