Worf is seriously injured when a support beam breaks and causes a heavy container to fall on him. He awakens in Sickbay to shocking news — he is paralyzed from the waist down. Dr. Crusher informs her patient that she has sent for a specialist, a neuro-geneticist named Dr. Russell, but stresses to Worf that his chances of gaining full recovery of his legs are minimal at best. This news crushes Worf's Klingon pride, and he refuses to allow anyone, including his son Alexander, to see him.
Discussing Worf's case with Dr. Crusher, Dr. Russell suggests implementing a radical medical technique that is still in the experimental stages. Dr. Crusher refuses, unwilling to risk Worf's life when he is in no danger of dying. Worf, however, believes his life Is already over. He asks Riker to assist in his ceremonial suicide, citing the belief that no Klingon should live as an object of pity or shame, but Riker is torn. Later, Dr. Crusher and Dr. Russell visit Worf to discuss his options. They present him with implants designed to partially restore the feeling in his legs, but Worf refuses, telling them he would rather die than be less than the man he was. At this point, Dr. Russell tells Worf about the experimental surgery that could fully restore his mobility.
This move angers Dr. Crusher, who believes Dr. Russell is trying to use Worf as a sort of guinea pig to test her unproven technique. They argue outside Worf's quarters until they are called to assist with the survivors of the crash of another starship. There, Beverly is further angered when Russell's use of another experimental technique leads to the death of a patient. Unable to trust her colleague, she relieves Dr. Russell from duty.
Worf still refuses to consider the implants and insists he wants to die. Because of this, Picard tries to convince Dr. Crusher to let Dr. Russell perform the experimental surgery, but Beverly stands firm. At the same time, Riker confronts Worf, reminding him that Klingon law dictates that it is Worf's son, and not Riker, who is supposed to assist in Worf's death. Unable to deny this, Worf abandons the idea of killing himself, and asks to try Dr. Russell's surgery instead.
Dr. Crusher reluctantly agrees, and together, she and Dr. Russell perform the operation. While the technique initially appears to be a success, Worf suddenly goes into cardiac arrest — and dies on the table. Dr. Crusher tries desperately to revive him, but eventually is forced to acknowledge that he is gone. But thanks to a mysterious Klingon biochemical reaction, Worf suddenly revives a few minutes later and goes on to recover. Dr. Crusher, however, is unable to forgive Dr. Russell for endangering the life of her colleague and friend.