Detective Steve McGarrett (Alex O ' Loughlin), a decorated Naval officer turned cop, returns to Oahu to investigate his father ' s murder and stays after Hawaii ' s governor persuades him to head up the new team: his rules, her backing, no red tape and full blanket immunity to hunt down the biggest " game " in town.

Joining McGarrett is Detective Danny " Danno " Williams (Scott Caan), a newly relocated ex-New Jersey cop who prefers skyscrapers to the coastline but is committed to keeping the Islands safe for his 8 - year-old daughter; and Chin Ho Kelly (Daniel Dae Kim), an ex-Honolulu Police Detective wrongly accused of corruption and relegated to a federal security patrol, who is also a former protégé of McGarrett ' s father.

McGarrett vows to bring closure to his father ' s case while the state ' s brash new FIVE-0 unit, who may spar and jest among themselves, is determined to eliminate the seedy elements from the 50 th state.