a shuttlecraft indefinitely. Sarek, Spock's father, continues to be an ambassador for the next century until his final mission during which he and Captain Picard mind-meld together because Sarek shows signs of Bendii Syndrome ("Sarek"). He later dies suffering from this affliction, but not before giving Captain Picard key information for locating his missing son ("Unification"). Kang, Koloth, and Kor, the three Klingons featured in "Day of the Dove" (Kang), "The Trouble with Tribbles" (Koloth) and "Errand of Mercy" (Kor), continue to serve the Empire well into the 24th century. They appear in the Star Trek: Deep Space Nine episode "Blood Oath" in which Kang and Koloth are killed. Kor later appears in two more episodes: "The Sword of Kahless" and finally in "Once More Unto the Breach" where, fighting in the Dominion War, he dies honorably in battle. A younger version of Kang, from the era of Star Trek VI: The Undiscovered Country, later appears in the Star Trek: Voyager episode "Flashback". Hikaru Sulu, promoted to captain of the USS Excelsior in Star Trek VI: The Undiscovered Country, reprises his role from that performance in the Star Trek: Voyager episode "Flashback". Janice Rand also appears in that same episode. Arne Darvin, the Klingon disguised as a human in "The Trouble with Tribbles", appears in the Star Trek: Deep Space Nine episode "Trials and Tribble-ations" with the intent to return to Deep Space Station K7 in 2267 and assassinate Kirk, whom Darvin blamed for his disgrace in the Klingon Empire. Besides the above examples, numerous non-canon novels and comic books have been published over the years in which The Original Series era crew are depicted in The Next Generation era, either through time-travel or other means. In addition, many actors who appeared on The Original Series later made guest appearances as different characters in later series, most notably Majel Barrett, who not only provided the voice for most Starfleet computers in episodes of every spin-off series (including a single appearance on Star Trek: Enterprise, where the computers normally did not speak at all), but also had the recurring role of Lwaxana Troi in The Next Generation and Deep Space Nine. Diana Muldaur, a guest star in the episodes "Return to Tomorrow" and "Is There in Truth No Beauty?" of the original Star Trek series, played series regular Dr. Katherine Pulaski in the second season of Star Trek: The Next Generation.