McGarrett (Alex O'Loughlin) and the rest of the team will have their hands full trying to capture dangerous criminals when the CBS series "Hawaii Five-0" returns for its sixth season.

Enstarz reports that one of the first cases Five-0 will break is when an unknown assailant threatens Oahu with a series of bomb explosion if arsonist Jason Dunclair (Randy Couture) will not be released from prison. The gang apprehended the murderous pyromaniac last season, but it appears he has an accomplice outside who is willing to do deals for him.

When a bomb squad is attacked and the culprit warns the police that he has planted additional explosives and will detonate them if they do not follow his demands ASAP, McGarrett and the rest will have to race against time to make sure their town is safe. Will they end up releasing a dangerous criminal? Knowing Five-0, they will think of a way to capture the abettor and keep Dunclair in jail.

Meanwhile, a promo video posted by showrunner Peter Lenkov on his Instagram account shows Chin Ho Kelly (Daniel Dae Kim) in his most dangerous form to date. In the short clip, he is seen looking down at a goon he previously managed to take down. Chin is holding a gun while flicking a badass glance towards the camera.

It certainly appears that the gentle Asian and the other members of Five-0 are readying themselves to face the bad guys wanting to cause chaos in their paradise. Lenkov teased that in an episode currently untitled, Chin, McGarrett, Kono Kalakaua (Grace Park), and Danny Williams (Scott Caan) will undergo a thorough but hilarious training under Lou Grover (Chi McBride) and Dr. Max Bergman (Masi Oka).

The promo images released show the team having some fun while navigating the obstacle course set out for their drill. In one instance, Danny can be seen crawling in mud with McGarrett egging him on to finish the task.

"Hawaii Five-0" will return on Friday, Sept. 25, at 10 p.m. EST on CBS.