On the latest "Hawaii Five-0," an unlikely pair teamed up to investigate a homicide. 

In "O Kela Me Keia Manawa," McGarrett (Alex O'Loughlin) and Grover (Chi McBride) team up when Jack, a friend of Grover's, goes on the run after killing a gangster and injuring the thug's associates after the confrontation. Chin (Daniel Dae Kim) discovers that Jack is wanted in Illinois, and gets one of the gangsters to confess that they were hired to kill Jack.

Grover and McGarrett track Jack through the forest and eventually arrest him. Chin captures the man who put on the hit, who is the distraught husband of Jack's victim in Illinois. Jack apologizes to McGarrett and Grover for killing the man's wife.

Meanwhile, Danny (Scott Caan) investigates the freak shooting of a woman he was flirting with after a bullet somehow passed through a tiny gap in her car window. He discovers that the gunshot came from a boat, where a boy was doing aiming practice.

Kono (Grace Park) also finally finds Adam (Ian Anthony Dale) and returns home to Hawaii to reunite with the 5-0 team.

The next episode will be called "Hana Lokomaika'i," which means "The Favor."

The episode will focus on Chin's father's murder, which occurred 15 years ago. His father was killed in cold blood during a robbery, and the investigators may have finally found out the identity of his father's killer. 

The synopsis reads: "A homicide investigation leads Internal Affairs to question Chin about the day his father was murdered. Meanwhile, Chin's relationship with Malia is explored and her brother's involvement in the homicide."

Watch the promo below for "Hana Lokomaika'i," which airs Friday, Jan. 17 at 9 p.m. on CBS.