Private cardiac surgery clinic partner Dr. Ludger Kreilinger dies in his car from a shot in the heart. Kreilinger's clinic partner professor Markus Huber's sports car left trails at the site, he claims Ludger was already dead when he arrived for a meeting. Kreilinger was cancer-terminal and shot with his own gun, possibly suicide or mercy killing. Shattered fresh widow Kerstin offers alibi nor explanation, claiming to ignore his cancer. Manufacturer Thomas Gause sold cheap bypass equipment to prof. Huber which are only approved for veterinary use, Kreilinger threatened to expose them, so Huber is arrested. IT specialist Rico Sander however finds a suspicious patient death in a routine surgery Kreilinger and Huber performed recently.