The SOVA detective agency is investigating a series of mysterious murders. All the crimes were dissimilar in manner, but the dead men knew each other, and for some reason they were killed on Thursdays. It turned out that all the victims were clients of a company that provided unfaithful husbands with an alibi during their absence. The company prepared travel documents for the men, round-trip air tickets, hotel bills, photographs with the required cities in the background, and even witnesses. Having received this kit, the guys could have fun with the girls in an estate near Moscow for a week. Very convenient!.. And then someone takes revenge!..