Proposals and reunions are the order of the evening for Hawaii Five-0's third episode.

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Catherine Rollins is back, and Steve McGarrett is ready to pick up right where the couple left off a year earlier. Well, not exactly where they left off - the Five-0 leader wants to take things to the next level, and he will be prepared to do so in "Ua 'o'oloku ke anu i na mauna (The Chilling Storm is on the Mountain)."

First, however, the former Navy SEAL must solve a double murder when a weapon links to disparate crimes together.

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"While Five-0 investigates a scuba diver's death from a gun recently used in another murder, McGarrett prepares to propose to Catherine," CBS teased of episode 3.

Meanwhile, Detective Danny Williams will get a visit from his nephew. Eric Russo (Andrew Lawrence) made his Five-0 debut in season 3 as a troubled high school grad that needed a little help getting his life on track. After solving a case alongside his uncle, Eric decided to work towards becoming a crime lab tech, a job that he may finally have in season 6.

"Ua 'o'oloku ke anu i na mauna (The Chilling Storm is on the Mountain)" will air on Oct. 9.

Head back to paradise when Hawaii Five-0 returns to CBS on Sept. 25 at 9 p.m. ET.

Tags: Hawaii Five-O television CBS