Retired Günther Pfeifer's corpse is found in his home freezer. Prof. Wolter presents the case to her forensics students, but the thermostat is sabotaged, plausibly by one of them. Notably assertive Svenja Reuter's spineless mother, Ursula Reuter, was his partner while colleagues at the college mess. Pfeifer's probably last contact was his alleged biological son -according to the late mother- Frank Köster, who was filmed using his card in an ATM posthumously. Shielded by teen home minder Wilhelm Häberle, Frank only to have found and hidden the corpse. Ursula admits having seen her ex for a debts claim. Brilliant forensics assistant Benedikt Förster supplies the crucial clues. Jo is aloof from the case, given his own doubts whether to get back together with Henrietta.
—KGF Vissers