Ensign Stone was a Starfleet officer whose first assignment out of Starfleet Academy was aboard the USS Tombaugh, under Captain Blackwood. Stone noted that his first week of active duty was a nightmare, even after four years at the Academy. Stone, along with the rest of the crew of the Tombaugh were assimilated by the Borg in 2362, a fact that was unknown at the time by Starfleet Command.
In 2375, when the USS Voyager encountered a Borg neural interlink frequency, Seven of Nine began to experience the personalities of various assimilated individuals, including Stone. (VOY: "Infinite Regress")