No Good DeedWhen Idris Elba wants to be scary, oh, can he be scary!

The guy who was so powerfully menacing as Stringer Bell on "The Wire" and brooding as a detective on "Luther" once again taps into his dark side in "No Good Deed." Elba plays a stranger who kidnaps a former district attorney (Taraji P. Henson) and her two young children.

In this exclusive clip, Elba shows how far he's willing to go to evade the law when Henson's car is pulled over by the police. He grabs her baby out of the back seat, growling, "It's just a little motivation to keep your mouth shut." But can she do that when the policeman asks her to step out of the car?

Find out, when "No Good Deed" hits theaters September 12.

No Good Deed- Clip No. 1