A simple surveillance job takes a tragic turn when an armed gunman shows up to kill a cheating husband they were monitoring and put bullet holes in both Catherine (Michelle Borth) and Billy Harrington (Justin Bruening) that only one of them will survive. Despite her injuries, Catherine refuses to remain in the hospital and works with McGarrett (Alex O’Loughlin) and Five-0 to uncover the reason for the double-murder and an expert cover-up that destroys almost all the evidence from the crime scene.
Aside from his wife (Monica Creel), who had motive for wanting her philandering husband dead, Five-0 also discovers the victim was using his wife’s security clearance to sell government secrets to a private competitor who is responsible for cleansing the crime scene to hide their involvement with the victim. The murder, however, had far more lascivious motives involving the husband’s high-class prostitute of choice (Lacey Beeman).
Much of the episode deals with the murder and Catherine and McGarrett dealing with the loss of an old friend. There are also a pair of B-stories involving the return of Joe White (Terry O’Quinn) whose help McGarrett enlists to find his missing mother and Chin Ho (Daniel Dae Kim) trying to talk Kono (Grace Park) out of doing something foolish when Adam (Ian Anthony Dale) decides to turn himself over the the Yakuza in order to save her life.
I’m a little disappointed that Kono’s story draws the short-straw again as I was hoping Hawaii Five-0 would offer Park the opportunity to lead an entire overseas episode (as they have done for O’Loughlin several times over the show’s previous three seasons). The death of Billy literally kills the growing uncertainty McGarrett felt of his girlfriend working for her ex-boyfriend which the show spent weeks to set up. However, it also frees Catherine for a new position, possibly with Five-0?