21. Forever

A murder aboard a luxurious 747 and the discovery of two formally attired teens in the desert confound Grissom and his crew in this absorbing episode. First, a horse trainer is found dead in the cargo bay of a private jet carrying 12 well-heeled passengers and a million-dollar show horse. Initially, it appears the victim was trampled to death, but Grissom and Catherine uncover evidence of foul play. Meanwhile, in the Hell's Gate section of Death Valley, Sara and Warrick probe the apparent suicide of a 15-year-old boy found under a bedspread. The investigation intensifies when a girl's body turns up a half-mile away.