Who and why needed to cruelly and calculatingly eliminate four girls who had been friends since youth? One dies at a holiday table after being poisoned by mushrooms. Another burns alive in her own apartment. The third barely avoids death in a car accident, and the fourth is pursued by a maniac killer… Who is he? Where should his trail be found—now or in the distant past, when the four were passionately involved in parachute sports and their main passion was risky jumps?..