Mechanic Mirko Bode is skull-smashed while returning a revised car. Mirko's depressive ex-girlfriend Lisa Geers was recently dumped. His boss Sigrid Baltes planned to make Mirko a partner, despite his criminal record, her brother Peter Baltes doubted if Mirko really turned the page. The investigation finds various machinations, yielding various suspects, also from private life, due to infidelity and abuse.