More than anything else, Katya Plotnikova dreams of losing weight; excess weight noticeably spoils her personal life. Is it possible to win the heart of the man you love, being so plump? It has long been known: most representatives of the stronger sex prefer slender, long-legged skinny women. That is why Katya immediately agrees to her friend’s offer to become a member of the test group, which is leaving for a country boarding house the other day. They are going to test a new weight loss drug. The medicine turned out to be simply miraculous! Katya managed to lose those extra pounds. But upon returning from the boarding house, the girl learns that two women from her group died suddenly, and the third was thrown under a subway train. And Katya was attacked at the entrance by a stranger, clearly not with friendly intentions...