The Stuttgart public prosecutor Söderhofer is beside himself: Ralf Grobe, a successful entrepreneur who had been awarded contracts for the controversial Stuttgart 21 project, has vanished without a trace. Like several others, he had previously been severely threatened by a recently released convict. While Chief Detective Steffen Braig initiates the search for the man, the remains of the missing person are found on the edge of the Stuttgart-Hohenheim palace park. Grobe was killed with two shots. What initially appears to be a routine investigation quickly turns into a criminal nightmare, as an anonymous confession letter declares: I am the second pig that must pay. The others will follow! And the urgently suspected ex-convict is nowhere to be found. Even more serious is the fact that the others are also missing.