Sonnenberg board pupil Nikolas Resche is frog poison dart-murdered while jogging. Rico joins the field team, fascinated by Nikolas's brilliant loner classmate Ira Belling whom he once mobbed, an unpopular Goth, prime suspect given access and ample knowledge of the exotic MO, she even keeps fit Amazonian frogs. Also suspect are teacher Karsten Reinhardt, who also read Ira's paper on frog poison, and Nicolas's former roommate, womanizing jock Sebastian Brinkhof, who states he disliked apparent homoerotic interest. Shortly after Ira is also prime suspect for the murder of Karsten Reinhardt, stabbed in his room, but the cases aren't necessarily linked. Rico also finds evidence that principal Tanja Schulz had an illegal affair with a pupil, but not Nikolas as first appears. By the time Jo puts it all together, another poison dart is kept ready.