One by one, members of the Montgomery family have died in tragic accidents. Sarah Montgomery, the last surviving member of the aeronautics dynasty, suffers amnesia and extensive injuries that leave her unrecognizable when she's hit by a cab.

Industrialist Trent Caldwell already harbors guilt over the death of his wife and now feels responsible for Sarah's injuries. After her surgery, he brings her to his home to recuperate. Mrs. Kearn, his housekeeper and surrogate mother, sees in Sarah someone capable of bringing Trent back to life. She begins playing matchmaker.

But the Montgomery family deaths weren't accidents. Someone harbors a deadly secret, and using skills perfected as a youthful IRA operative, has systematically eliminated the family out of a need for revenge. Realizing Sarah's true identity, the assassin now has one more kill to make in order to fulfill a promise made long ago.