Tom is obsessed with finding the elusive jungle girl. The Porters locate her cave, but Christa is vary wary. Matters are complicated by a rare confluence of the triple moons, which causes all the animals, including Tasha, to become dangerous. The Porters ultimatley learn that Christa also come from twentieth-century america.

A twelth-century knight stumbles into the Land of the Lost and recues Christa from Sllestaks. Kevin who has a crush on Christa, is jealous of the attention the knight recives. Later, the knight commits several blunders and confesses to Kevin he has lied: He is not a knight, just a lowly squire.

Returning to their treehouse compound, the Porters find thet land in the grip of a withering drought. But to get fresh water, they must risk exposing their homebase location to the vile Sleestak lizard-men.