As the episode begins, Lt. Worf fails to report to his Bridge duty station and Lt Commander Data and First Officer Commander William Riker become concerned. Riker finds Worf's quarters filled with incense and burning candles while his Chief of Security sits before a small fire nearby in a nearly trancelike state.
A repentant Worf explains to Picard that he was attempting to reconnect with his Klingon spiritual beliefs by performing a Klingon ritual in an attempt to summon a vision of Kahless, the original messianic warrior who founded the Klingon Empire.
Picard responds to Worfâs crisis of faith by suggesting he immerse himself in Klingon culture, and grants him leave to journey to the Temple of Boreth, core of Klingon beliefs concerning Kahless.
After ten days of doubt-filled rituals, he sees what he thinks is a vision of Kahless. It is not, it is an actual being.
Worf brings the prospective spiritual leader to the Enterprise, but is troubled that Kahless doesn't remember how Klingon Warnog tastes, or what Sto-Vo-Kor, the Klingon afterlife is like.
Klingon Chancellor Gowron arrives, saying he has a test which will indisputably prove if Kahless is genuine. Gowron is displeased with the prophetâs return, convinced he is an imposter foisted by the priests to gain power and could incite a civil war. Gowron requests that the Federation genetically test the sacred dagger he brought which was stained with the blood of the original Kahless in antiquity, but is disappointed when the test indicates a match.
Gowron provokes a D'k tahg duel with Kahless and wins, leaving a dispirited Worf to ponder how the supposed "greatest warrior of all" could be beaten.
Worf demands an explanation from Koroth, the High Priest of the Boreth Temple, who disconsolately replies that Kahless isnât a resurrection, only a clone of the original, offering the rationale that the legend of Kahlessâ return didnât specify the exact manner. He adds that such a legend is desperately needed to rally the peopleâs faith and guide them.
Chief Operations Officer Lt. Commander Data advises the uncertain Worf that once during a crisis of his own he made the leap of faith to "assume that he was a person," and thus could grow beyond the sum of his programming.
Gowron is outraged when Worf tells him the truth and prepares to execute the clone and priests. Worf tells Gowron he has decided to support Kahless, explaining that he has made a leap of faith as Data once did, adding that the cloneâs origins donât matter. He suggests the Klingon High Council appoint Kahless to the ceremonial position of Emperor, while only a figurehead, he could hopefully unite the Klingon people. In conclusion Worf observes that while not the âtrueâ Kahless, this man is at least the "Rightful Heir" to Kahless; opposing him might lead to civil war. Seeing the wisdom of cooperation, Gowron offers his devotion.
Departing soon after for the Klingon homeworld Qo'noS, Kahless notes the troubled demeanor of the 'Son of Mogh' and reassures him by observing that the personal belief systems espoused by Kahless made the ancient Klingons what they were, the man was not important; even if the real Kahless never returned it might not matter, as his spirit lives within the heart of all true Klingons.