Twenty-three-year-old law student Maria Kallio is recruited for a temporary position at the Helsinki police department. Sweet-faced but tough and hot-tempered, Maria faces pushback from her new squad – so when a young playboy is murdered at his family's summer villa, the new detective is out to prove herself. Found floating facedown at the water's edge after a night of partying, Tommi Pelatonen appears to have been murdered by one of his closest friends – but why? As Maria discovers, bitter passion and jealousy seethe under the placid surface of the group's privileged, carefree lifestyle. As Maria uncovers the victim's unsavory secrets, motives for all seven suspects come to light. Now it's up to her to untangle the clues before the killer strikes again.