 A few crossover appearances, such as that of Spock on "" and the time-travel of the crew of "" to the era of "" were especially lauded by both fans and critics.After the original series, a character from an earlier series appeared in the premiere episode of each new series.These were the appearances of Leonard McCoy in "Encounter at Farpoint", the first episode of "The Next Generation"; that of Captain Jean-Luc Picard in "", the first episode of "Deep Space Nine"; Quark and Morn in "", the premiere of "Voyager"; Zefram Cochrane (from the original series episode "" and the film "") in "", the premiere of "Enterprise"; and Sarek in "The Vulcan Hello", the first episode of "Discovery".