"e Sea Serpent is the thirty-first installment to the Magic Tree House series and the third of the Merlin Missions. During this mission, Jack and Annie meet Teddy's friend Kathleen who later helps them regularly on adventures and is a possible love interest for Jack."@en . . . . "e Sea Serpent is the thirty-first installment to the Magic Tree House series and the third of the Merlin Missions. During this mission, Jack and Annie meet Teddy's friend Kathleen who later helps them regularly on adventures and is a possible love interest for Jack."@en . "Summer of the Sea Serpent"@en .