The "Hawaii Five-0" team is already having a difficult time dealing with the island's criminals and with Gabriel Waincroft, but now it appears the FBI is also on their case. Unfortunately, McGarrett and the others are unaware of the FBI's interest. But what they do now is they have to save an important informant.

Fans were treated to another nail-biter of a show in episode 15 when Chin Ho (Daniel Dae Kim) caught up with Gabriel (Christopher Sean) and the two engaged in a vicious fight which ended with the "Five-0" member throwing his brother-in-law out of the window. Unfortunately, Gabriel managed to survive the three storey drop and escape. Elsewhere, Danny (Scott Caan) and his mother were questioned by the FBI about Matt. But it turned out to be a fishing expedition by the bureau who wanted to trip Danny into admitting that his team was using illegal resources. Viewers also learned that Abby (Julie Benz) was actually an FBI agent who's tasked to observe the team and arrest them if they cross the line.

The team is currently in the dark of Abby's true assignment, but they do have their hands full with their new case. According to a Spoilers Guide synopsis for episode 16, "Ka Pohaku Kihi Pa'a" or "The Solid Cornerstone," McGarrett (Alex O'Loughlin) will ask his old friend and barber, Odell Martin (Michael Imperioli), to defend one of "Five-0's" informant when he is accused of murder.

A trailer for the upcoming episode shows Odell breaking down the situation about his new "client." He enumerates to McGarrett that they have "no witnesses, no leads, just the word of a career criminal." Interestingly, the career criminal is no other than Sang Min (Will Yun Lee). There are scenes of Sang Min slowly putting his hands up, McGarrett running after someone and a court room. McGarrett seems to believe that Sang Min is innocent.

The episode described as the "most dramatic" episode so far as Chin Ho and the others are shown involved in a shoot-out at the docks. The clip ends with guest star Ziggy Marley's arrival.

While fans are undoubtedly anticipating how things will turn out for Sang Min, most are also wondering about Abby and her feelings for Chin. Benz recently talked to TV Guide about the shocking revelation about her character and reveals that she thinks her character "developed real feelings for Chin over time."

The team will reportedly discover the truth about Abby soon. However, that doesn't mean it's the end of Abby and Chin's relationship as Benz believes there's hope for the two.

Episode 16 of "Hawaii Five-0" season 6 will be aired on Feb. 26.