A mystifying serial murder in vibrant Berlin brings experienced and persistent inspector Carolin Schwarz to her criminalist and emotional edge. To help clear up the case, she is unwillingly paired with her predecessor superintendent Paul Schmidt, an odd man who was, and still is, adored by their colleagues. Paul doesn't concern himself with the rules that were or social conventions. After some suspicion and distrust, Carolin slowly begins to take his often politically incorrect and unconventional investigation methods to heart and even begins to admire them. Two sympathetic individualist oddballs with the same goal but very different approaches become a team that can solve even a case as complex as this one, with a bit of humor and good instincts.