The Case of the Underwater Aliens: Book 3 - Chi-hyeon Ahn

Strange glowing aliens have been spotted near Seagull Island! A fisherman claims he saw a mysterious underwater creature near the shore. He believes it's an extraterrestrial, so he asks the Mystery Science Detectives to take the case. It's a smart call since the after-school club can solve any mystery using the power of science! But when the mysteries begin to multiply, the team wonders if they're in over their heads this time.