Evolution (Star Trek: The Next Generation) neutronium as a result of a stellar explosion that occurs every 196 years and is due to occur in the next few hours. Stubbs plans to launch a probe, dubbed the Egg, to gather the data, a result of a lifetime's development. Meanwhile, Chief Medical Officer Dr. Crusher (Gates McFadden) has returned to her duties on the "Enterprise" after a stint at Starfleet Medical. As the expected time of the stellar explosion nears, the ship malfunctions in odd ways, and the issue is traced to the computer core. Acting Ensign Wesley Crusher (Wil Wheaton), who had been working on a
Star Trek: The Next Generation Farpoint" with 15.7, and "Justice" with 12.7. The season ran from 1987 to 1988. The series underwent significant changes during its second season. Beverly Crusher was replaced as Chief Medical Officer by Katherine Pulaski, played by Diana Muldaur, who had been a guest star in "Return to Tomorrow" and "Is There in Truth No Beauty?", two episodes from the original "Star Trek" series. The ship's recreational area, Ten-Forward, and its mysterious bartender/advisor, Guinan, played by Whoopi Goldberg, appeared for the first time. Owing to the 1988 Writers Guild of America strike, the number of episodes produced was cut from 26