Three high-school students, two boys and a girl, are suspected of having fired a gun that was used in a serious crime committed over 30 years ago. The perpetrator, who at the time had shot an innocent student while on the run after robbing a bank, was never caught.
The three high-school pupils firmly deny being in possession of the weapon and provide a false alibi, and so – also for personal reasons – public prosecutor Mehlhorn calls in Bella Block to do some undercover detective work at the college. If the weapon could only be found and traced, it might yet be possible to bring the original culprit to justice.