故事紧接上一季结尾:夏威夷州长遭谋杀后,Steve McGarrett成了头号嫌疑人,被临时羁押在监狱里等候出庭受审。Danny突然带着能够洗清他罪名的证据前来探监。与此同时,Kono遭到停职检查的处分,内务调查部派人对她展开全面调查。Terry O'Quinn在本集中扮演McGarrett在海豹突击队受训时的指挥官Joe White;Richard T. Jones扮演新任夏威夷州长Sam Denning;William Sadler再次扮演McGarrett的父亲John McGarrett。Steve McGarrett has been arrested and jailed as sole suspect for governor Jameson's murder, on security tape, in fact being set up by Wo fat himself. Hitman Victor Hesse, father McGarret's murderer, stabs him during exercise, but as a ploy to enable Steve's escape, fearing Wo fat will dispose of all 'loose ends' lethally. Lieutenant Governor Denning, acting, mandates I.A. to clean up, which includes suspending Kono. Danny and Chin keep working within the police, ultimately joined by Steve to clear him and prove Wo Fat's guilt, meanwhile discovering a convoluted plot of crimes centered on dirty bomb-grade nuclear material with a surprising purpose.