McGarrett and his team launch a manhunt for two passengers who escaped through the wheel-well of a plane shortly after it landed. The plane was on lock-down because a US Marshall was murdered just as the plane started its descent. The Marshall was a friend of Danny's from New Jersey and it turns out he was calling Danny when he was murdered. The team quickly finds the first escapee, he was the Marshall's prisoner and he claims not to know the man who helped him escape. While Five-0 tries to find the second escaped passenger (known to them by his fake ID, McGuire), Danny gets a call from him. Turns out "McGuire" is Danny's former partner, whom Danny put in jail. He's out to ruin Danny's life and has kidnapped Grace. Unable to contact Five-0, Danny must follow his ex-partner's instructions in order to rescue Grace.