"Hawaii Five-0" episode four of season six finds Adam being kidnapped by the Yakuza and the crew solves a murder and kidnapping case related to previous characters from earlier episodes of the show.
"Hawaii Five-0" season six and episode four opens up with Adam getting abducted in an elevator. He wakes up to find himself in an abandoned warehouse where he is facing the Yakuza's Tom Bishop. According to Entertainment Weekly, Bishop acquits Adam of any connection with the death of the men found in his house. However, Bishop tells him that he still owes them money. The Yakuza is looking for the cash that Gabe took from Adam and it has been weeks. They have finally decided to come and deal with it themselves.
Meanwhile, the "Hawaii Five-0" team is given a case of a couple who found fake money in the Makua Forest Reserve that belongs to a dead man. They discover that the cash belongs to Miko, last episode's victim. The corpse buried in the woods turned out to be that of Harrison Crane, Hawaii's richest man who disappeared without a trace. The couple who found the money and the body was exonerated and the death ruled as accident.
In a post by Movie News Guide, the team goes to Crane's mansion where they discover that Crane's daughter Laura has been kidnapped. They soon linked the fake cash to a painting sold by Gerard Hirsch an art appraiser. The kidnapper calls Hirsch for the art work but he already sold it.
"Hawaii Five-0" chases down the man who bought the painting, secured it just in time and caught the kidnapper who was trying to escape when he was hit by a truck. Later, it turned out that it was Crane's maid who orchestrated the kidnapping to get money for her son who was the kidnapper.
