Books for boys of this age are almost consistently better than books for girls. Here is another good adventure yarn --Arctic locale -- mystery -- melodramatic but credible -- with a touch of timeliness in a Nazi spy. Hector, at 19, wants to join the RCAF, but his training makes him valuable in another direction, as assistant to a scologist assigned to the crew of the Narvic, instructed to keep eyes and ears open. He sees plenty -- and after a succession of adventures, helps unmask the ship's captain. Good local color -- fast paced story.