'Hawaii Five-0' season 7 spoilers, casting news: Kono and Adam reunite in episode 5; 'Rookie Blue' alum Missy Peregrym joins cast

Five-0 discovers a cache of guns stolen from a gun range in the upcoming episode of CBS' procedural drama "Hawaii Five-0" season 7.

Titled "Ke Ku 'Ana (The Stand)," this week's episode will feature a culprit plotting to make a deadly statement on gun violence. According to the official synopsis for episode 5, a cache of guns is stolen from a gun range, and Five-0 discovers the culprit is planning a dramatic and possibly fatal statement on gun violence. Elsewhere, Kono (Grace Park) and Adam (Ian Anthony Dale) are reunited when he is finally released from prison.

On another note, actress Missy Peregrym will be joining the ranks of "Hawaii Five-0" season 7. The "Rookie Blue" alumna will be introduced in this season's episode 10 as Danny Williams' (Scott Caan) sister, Bridget. Although she still resides in New Jersey with her husband and kids, she goes to Hawaii alone for a corporate retreat. While seeing his sister in a professional setting, Danny will be surprised to discover a different side of her he has never seen. Peregrym's most recent project was "Motive," in which she appeared as a guest star. Some of her other acting credits include "Stick It," "Reaper," "Heroes," and "Life As We Know It."

Meanwhile, series regular Alex O'Loughlin, who plays Lieutenant Commander Steve McGarrett, will reportedly leave "Hawaii Five-0" after season 8. According to the actor, his decision to exit the program is attributed to his physical health. "I've taken so many physical hits on this show, my back is pretty bad and I've got a lot of fixing I've got to do. I've got to fix my body," he explained.

With O'Loughlin's impending departure, Steve's partnership with Danny hangs in the balance. To date, execs have yet to confirm how Steve will be written out of the story or if he will be recast.

The seventh season of "Hawaii Five-0" airs every Friday night at 9 p.m. ET on CBS.