Film's protagonist is Dr. David Krane (played by Ray Liotta), Seattle medical examiner haunted by the unproven allegation that he murdered his wife some years ago. The case against him was dismissed because of tainted evidence and Krane can hardly convince anyone of his innocence. When he is called to the multiple murder site, he finds some clues that this could be work of her wife's real killer. But Krane's friends within police aren't interested in further investigation, so Krane must resort to more drastic and desperate alternatives. One of them is provided by Dr. Martha Briggs (played by Linda Fiorentino), scientist convinced that spinal chord fluids store people's most important memories. Her experiments with rats have shown that injection of those fluids could allow a person to relive other people's memories. Dr. Briggs believes that it would take years for such procedure to be tested on humans, but Krane can't wait. He breaks into her laboratory, steals her formula and later injects spinal chord fluids of his dead wife and few other murder victims into himself. The experiment succeeds and Krane continues investigation, caring very little about life-threatening side effects and the danger that lurks from the killer.

John Dahl is talented director, and for this project he gathered talented cast. Ray Liotta is great actor who is more than able to play complex characters, and his colleagues in supporting roles are talented too. Unfortunately, all this talent is in vain when confronted with incredibly uninspired script by John Geddie. Just like in many Hollywood's "high concept" thriller, potentially intriguing idea is wasted for the sake of lame murder mystery. Naturally, the plot is reduced to the series of cliches, including red herrings and spectacular confrontation at the end. But the most disappointing of all is to see Linda Fiorentino, fresh from her acting triumph in LAST SEDUCTION, being reduced to such one-dimensional cartoonish and utterly unnecessary character. Such script could have provided material for hilarious parody, but Dahl directs it with complete seriousness, obviously believing in the possibility of technology presented in this film. Dahl probably thinks that one day people could bring back memories via specials serums. For movies like UNFORGETTABLE they would need unusually high doses of such stuff.