The speed cameras on the southern bypass have often been the target of tampering. However, when one of the small gray boxes is blown up one morning during the busiest rush hour, it takes on a different significance, especially since a driver dies of a heart attack in the process. Is this reckless mischief with fatal consequences? Or a serious attack? Commissioner Petzold approaches the case methodically—until a claim of responsibility surfaces, threatening further attacks. A second bomb causes a devastating rear-end collision with multiple fatalities. Not only Petzold but also the public is alarmed when the newspaper publishes a second claim of responsibility. The city is in turmoil. A frantic search begins.