'Hawaii Five-0' season 7 episode 17 spoilers: Chess Piece Killer surrenders to HPD; crossover event with 'MacGyver' coming next month

The Chess Piece Killer is back on the next episode of "Hawaii Five-0." However, it's either she's up to her usual mind games, or she may completely be out of commission.

Titled "Hahai i nā pilikua nui (Hunting Monsters)," the episode will feature the infamous Dr. Madison Gray (Elizabeth Röhm) in a surprisingly incapacitated state as she stumbles into the Honolulu Police Department (HPD) covered in blood. And as if this isn't enough of a shock, she will also claim to have lost her memories.

Gray has already proved to be quite the actress before, so believing her may not come easily to Steve McGarrett (Alex O'Loughlin) and his team. But they will definitely get to the bottom of this in one way or another, especially since the blood on Dr. Gray ends up being a match to that of former FBI profiler Alicia Brown (Claire Forlani).

The promotional images tease that the two women will have their own sweet time together when Alicia pays Gray a visit during the investigations. One particular image even shows the former profiler threatening the police psychiatrist-slash-serial killer's life with a sharp object pressed to her neck. Viewers can remember that during their previous encounter, Gray almost indirectly caused Alicia and Steve's deaths.

Will this be an episode of reckoning or one of forgiveness and closure? What happened between Alicia and Gray prior to the latter's trip to HPD? Is her claim of amnesia just an act, or has she really been given a chance to start over with a clean slate?

"Hawaii Five-0" season 7 episode 17 airs on Friday, Feb. 17, at 9 p.m. EST on CBS.

In other news, the Phoenix Foundation is coming to Hawaii for a crossover event on the March 10 episode of CBS' "MacGyver." According to TV Line, Angus MacGyver (Lucas Till) and Jack Dalton (George Eads) will be teaming up with Five-0's Chin Ho Kelly (Daniel Dae Kim) and Kono Kalakaua (Grace Park) on a mission to rescue a group of government scientists trapped in a building after an earthquake hits Hawaii. Taylor Wily, who plays police informant and shrimp stand proprietor Kamekona, will also be making an appearance, as shown in an image posted by Till on his official Twitter account.

"This crossover has almost seemed inevitable since the day 'MacGyver' premiered," Peter Lenkov, who is the executive producer for both shows, said in a statement. "We have always envisioned that our H50 ohana and the Phoenix team live in the same universe, and it was about time that Mac and Jack had a case in Hawaii," he added.