Keenan was a 24th century individual. By the mid-2360s, Keenan was serving as an operations division lieutenant in Starfleet, assigned as a security officer aboard the USS Enterprise-D. In early 2366, Keenan was next on the duty roster to provide security on a landing party mission and was due to accompany Lieutenant Commander Data and Lieutenant Geordi La Forge to the planet Kirlos. However, Security Chief Worf volunteered for the mission, and he was chosen to accompany the mission by Commander William T. Riker. (TNG novel: Doomsday World)