Heeeeep! (covers mouth)

[delicatale]

Hawaii Five-0 has landed another well-known actor for its second season: Tom Sizemore is joining the CBS action-drama as a the head of Internal Affairs for a multi-episode arc.

The tough-guy performer best known for Saving Private Ryan, Red and Black Hawk Down will play a former Detroit Homicide Detective turned head of Hawaii police’s IA unit. After the events of last season, he is actively investigating the Five-0 unit and he’s not cutting them any slack (despite our heroes having the support of the new Governor).

The casting comes on the heels of Lost star Terry O’Quinn signing onto the series last week in a recurring role as a Navy Seal Lt. Commander who trained Steve McGarrett (Alex O’Loughlin).

Hawaii launched strong last fall and represented one of the few freshman shows to earn a second season. The cast additions could help bolster interest in the series this fall as it continues airing in its competitive Monday night period.

OMG TOM SIZEMORE OMG YESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS.