A young woman unexpectedly commits suicide in a cafe. She leaves a mysterious note. Her companion disappears unnoticed. It turns out that the suicide’s husband also died, and the two previous spouses disappeared without a trace. And the case would have remained unsolved if not for Nastya, the beloved of the last husband of this “black widow.” She takes on the matter on her own. And if it weren’t for the spaniel dog, who once showed up at the cafe and stayed there waiting for someone, it’s unknown how things would have ended...