You just don't meet fairy godfathers in airports. Especially big New York City airports,"" says Trygve Samsen, aged twelve, to kid sister Solveig. But the little man with patches of violent red hair says yes, you do; he also insists that ""when you have an adventure, make it first class."" They do. Stranded because their parents' plane is delayed, Tryg and Sal follow Sam into Manhattan and a series of not quite explainable but highly believable episodes: taking an elevator out of the hotel, riding a spookhouse-type subway and a ferry that won't come closer than twenty feet to the dock, making the ball disappear between pitcher and catcher at Shea Stadium. The last could probably happen without Sam's magical nose but the rest are thoroughly entertaining (and sometimes have wry consequences). Tryg and Sal know Sam is special, also that their several day tour of Manhattan with some Frankweiler-type money problems--is seen differently by those around them, certainly by their parents when they finally meet up in the police station. The way Tryg tells it is a subtle blend of suspicion and delight--children will adopt Sam instantly.