Jenny Cole, the daughter of a friend of Joe Mannix, awakens after almost a year in a coma following a hit-and-run accident. But the celebration of her return to health is soon cut short when someone tries to kill Jenny. This leads Mannix to conclude that Jenny must have seen something on the day of the accident that she shouldn't have seen -- and that someone wants to tie up that loose end by "putting her to sleep" permanently.
—aldanoli