A survivor of the devastation of Earth's third World War, Sloane was somewhat used to seeing murder and people getting "a thrill from murdering someone… all the time" in the society that was left in the 2060s. From her perspective, money was still very much the driving force in people's lives.
On April 4, 2063, the missile silo where Sloane and Cochrane were constructing their warp ship came under fire by a Borg vessel from the 24th century. Despite the unwillingness of her partner, Sloane sought to protect the Phoenix from what she believed to be an attack from the Eastern Coalition.
In the aftermath, Sloane remained in the missile silo where she encountered Starfleet Captain Jean-Luc Picard and Lieutenant Commander Data, there to repair the timeline. Armed with a Calico M960 submachine gun, Sloane opened fire on the two officers, believing them to be members of the Eastern Coalition. Sloane was, however, felled by theta radiation leaking from the damaged Phoenix and transported aboard the orbiting USS Enterprise-E by Doctor Beverly Crusher.
Once aboard, Sloane was treated for severe radiation poisoning, but was revived by the medical staff when the Borg overran the Enterprise sickbay. Retreating to a Jefferies tube, Sloane slipped away from Doctor Crusher and her team, eventually coming across Picard. She held the Captain hostage until he was able to convince her that she was not in Montana anymore. Relinquishing the phaser to Picard, Sloane accompanied the captain in his effort to retake the ship.
Finally returning to the bridge of the Enterprise, Sloane was present for a heated exchange between Picard and one of his officers, Lieutenant Commander Worf. Following the captain into the adjacent observation lounge, Sloane chastised Picard for his actions, comparing him to Captain Ahab of Herman Melville's Moby Dick, despite the fact that she had never read it. Sparring verbally with the captain, Sloane was able to convince Picard to relent and follow Worf's recommendation to engage the ship's auto-destruct system.
Sloane departed the Enterprise along with the remainder of its crew in an escape pod bound for Gravett Island. Captain Picard refused to join the officers who were leaving the ship. When she questioned him, the captain admitted that he was going back to find Data. The Captain had told her that Data had helped save him from the Borg years before. The Captain, in turn, felt that he needed to save Data. Sloane was moved by this and told the captain to "go on and find your friend" She later reunited with Picard and his command crew, as well as Zefram Cochrane, back in Montana on the night of April 5, 2063. There, she witnessed Cochrane making his historic First Contact with a group of Vulcans. (Star Trek: First Contact)
Sloane was outspoken and a little high-strung, yet was a capable judge of character, being the first to recognize Captain Picard's emotional demons.
Lily Sloane was played by Alfre Woodard.
Her surname comes from the script. In the first draft of the script, she was named Ruby Sloane, a photographer and X-ray technician who was instrumental in helping Jean-Luc Picard repair the damaged Phoenix. The name Ruby was instead used for one of the Dixon Hill characters seen in the film.
The short story "A Girl for Every Star" in Strange New Worlds V established that a statue of Lily Sloane was created and placed outside the Sol Museum of Aeronautical Science.
In the novel Spectre, Sloane's descendants settled on Alpha Centauri IV, where the family name became a space exploration dynasty. Notable Sloanes included Zefram Sloane.
Sloane appeared via flashback in the second issue of the comic crossover mini-series Star Trek vs. Transformers where she and Zefram Cochrane are shown witnessing the Autobots leaving Earth aboard the Titan Fortress Maximus during the beginning of World War III.