New preview videos for the season 4 premiere of Hawaii Five-O revealed that Steve McGarrett's mother might have killed Wo Fat's father.

The released clips show the characters of Hawaii Five-O stuck in sticky situations. In one clip, detective Chin Ho Kelly (Daniel Dae Kim) ambushes one of the terrorists who invaded the Hawaii Five-O headqarters and held the people in the building hostage. The premiere will also feature one of the "least expected outcomes" to the hostage scenario.

The season 3 finale showed McGarrett (Alex 'O Loughlin) visit Wo Fat (Kigh Diegh) in maximum security prison and discover that WoFat was planning on using him as a human shield against enemies within the prison, who were trying to break into his cell.

In the other preview clip, McGarrett talks to Fat in another maximum security prison at joint base Pearl Harbor. Half of Fat's face is obliterated by raw burn scars. McGarrett asks Fat about why his mother came to see him in prison, to which Fat reveals that she came to apologize for kliing his father. McGarrett is left flabbergasted by this revelation. He accuses Fat of killing her husband (his father), and hunting her for twenty years.

"Why would my mother ever apologize to you?" he asks again, disregarding Fat's previous accusation.

"That is a question only she can answer," Fat replies.

McGarret takes Fat's head and smashes it against the iron bars of the prison cell, taking a blood sample on a cotton swab for investigation purposes.

Melanie Griffith will guest star as McGarrett's mother in the show. In the premiere episode, Aloha ke kahi I ke kahi, McGarrett will also break the law so he can find his kidnapped girlfriend, Lieutenant Catherine Rollins (Michelle Borth).

Aloha ke kahi I ke kahi airs Friday, Sept. 27, on CBS.

Watch the previews:

Tags: Hawaii Five-O Season 4 Spoilers CBS