A random accident critically injures Worf, paralyzing him from the waist down (and the prognosis is that the damage is permanent). A neurospecialist, Dr. Toby Russell, comes aboard and begins working with Beverly on possible treatments. After three days and no progress, Riker visits Worf in sickbay. He is appalled, however, to find that Worf considers his life over, and that he wants Riker to help him commit ritual suicide!

Meanwhile, with traditional treatments apparently ineffective, Dr. Russell mentions a new line of research she's been working in, that of "genotronic replication." If successful, it would leave Worf as good as new; but if not, Worf would die. Further, she's never used it on a humanoid before, and her success rate on holodeck simulations is only 37%. Beverly decides the risk to Worf is unjustifiable, and decides to continue searching more conventional options. Then, to make matters worse, word comes in of a crash- landed ship nearby with over five hundred people aboard, throwing the Enterprise medical staff into overdrive.

After Picard tells Riker that he cannot make Riker's decision for him (and exhorts Riker to keep as open a mind as possible), Troi comforts Alexander, who is angry at not being allowed to see his father (at Worf's own request). She later upbraids Worf for putting his honor above his son. Beverly and Dr. Russell arrive, and tell Worf of a treatment with artificial implants that would eventually result in his regaining about 60% of his mobility. Worf makes a halfhearted attempt to use the training device, but angrily rejects this line of treatment as repugnant. Russell, seeing an opening, quickly mentions her genotronic treatment, pointing out the possibility of a complete recovery. As they leave Worf to ponder this, Beverly angry upbraids Russell for overstepping her authority, and using a patient's desperation to advance her own research. Their conversation is interrupted, however, as the Enterprise reaches the crash site, and both doctors apply their efforts to the emergency at hand.

During this treatment, however, Russell oversteps her bounds and uses her own treatments rather than conventional methods on one patient. The patient dies, and a livid Beverly removes Russell from all medical duty. A few hours later, however, Picard quietly suggests to her that she allow Russell to use the genotronic method on Worf, pointing out to her that the choice Worf faces in his own mind is that of suicide or risking death for a full cure. An upset Beverly ponders this, while Riker confronts Worf about the suicide ritual. He angrily takes Worf to task for his attitude throughout the whole affair, and clinches matters by saying that Klingon custom does not allow Riker to be the one who assists; that falls to the oldest son (i.e. Alexander). Worf, unwilling or unable to ask Alexander to help him die, chooses the option of the genotronic treatment.

Beverly grudgingly allows the treatment, and the procedure begins (after Worf asks Troi to raise Alexander should he die in the process). While Picard, Riker, Troi and Alexander all busy themselves with nonessentials, things in surgery go smoothly, for the most part. However, once the new spinal column is in place and Worf's brain is taken off life support, he suddenly goes into cardiac arrest; and despite Beverly's best efforts, dies on the operating table. She tearfully tells Alexander the bad news-but when Alexander goes in to see him, Worf suddenly twitches. The Klingon anatomy's many "unnecessary" redundancies are the very thing that saved his life. Beverly stonily bids farewell to Russell, and Worf begins the road back to recovery.