Star Trek - Ishmael
The Enterprise is on a peaceful mission at Starbase 12 when a bizarre cosmic phenomenon causes a Klingon ship to suddenly vanish - with Spock aboard for the ride. Spock's last message from the Klingon ship is cryptic and frightening. The Klingons are travelling into the past, searching for the one man who holds a vital key to the future. If they can kill that man, the course of history will be changed - and the Federation will be destroyed!
Science fiction, Star Trek fiction, Time travel, Fiction, collectionID:ST#
Barbara Hambly
Barbara Hambly (born August 28, 1951) is an American novelist and screenwriter within the genres of fantasy, science fiction, mystery, and historical fiction. She has a bestselling mystery series featuring a free man of color, a musician and physician, in New Orleans in the antebellum years. She also wrote a novel about Mary Todd Lincoln.

Her science fiction novels occur within an explicit multiverse, as well as within previously existing settings (notably as established by Star Trek and Star Wars).