The "Hawaii Five-O" ohana is being threatened by a Russian spy. Does it have something to do with Catherine Rollins' secret mission?

The previous episode of "Hawaii Five-0" saw fan favourites Sang Min (Will Yun Lee) and Odell Martin (Michael Imperioli) return in a fun legal caper. With the "Five-0" informant accused of a crime he didn't commit, Steve McGarrett (Alex O'Loughlin) asked Odell to represent him. While initially hesitant, the easy-going barber dug deep into his legal background and successfully proved Sang Min's innocence.

Episode 16 showed that "Five-0" really has each other's backs, regardless of your past or background. Now it seems the team is being threatened once more, and by those close to them. According to a synopsis for episode 17, titled "Waiwai" or "Assets," Steve and the team scramble to find a Russian spy who has stolen a flash drive that contains classified NSA information. The case becomes personal for the team as the contents of the flash drive will put the life of one of their own at risk.

Aside from the case, it appears that Steve will finally discover what Catherine (Michelle Borth) has been doing and why she left. Meanwhile, Internal Affairs mole Abby Dunn (Julie Benz) continues to hide her real identity and mission from Chin Ho Kelly (Daniel Dae Kim) and the rest of the "Five-0" team.

Fans last saw Catherine in episode 3, when she left Steve to help in the aftermath of the Nepal earthquake. But it was quickly established that it was just a cover and that she was really on a secret mission. Now it seems that she will once again make her presence felt, when Steve appears to have already moved on.

Enstarz previously reported on this storyline several months ago. The site even posted an Instagram clip from "Hawaii Five-0" showrunner Peter Lenkov that showed someone questioning Steve regarding his ex-girlfriend's dropped calls.

The team is also unaware that there's more to Abby's assignment to "Five-0." The detective is actually working for Robert Coughlin (Ingo Rademacher), a federal prosecutor who has a personal grudge against the team.

Fans are no doubt disappointed that the romance between Abby and Chin might have been one-sided, something that Benz talked about with TV Line. According to the actress, the character bailed out on her date with Chin because she's actually falling for him. However, she also has a job to do.

"She's put in a really tough position where she has to decide between doing her job and following her heart," said Benz.

Unfortunately, fans would have to wait before the Abby and Chin drama is resolved.

"Hawaii Five-0" season 6 will return with a new episode on March 11.