Reese Witherspoon: 'Devil's Knot' with Colin Firth!

Reese Witherspoon hits the tennis courts at a country club on Wednesday (May 16) in Brentwood, Calif.

This June, the 36-year-old actress will start work on her new project, Devil’s Knot, which also stars Colin Firth, reports THR.

PHOTOS: Check out the latest pics of Reese Witherspoon

The film is based on the 2002 bestseller by investigative journalist Mara Leveritt.

Devil’s Knot is about the savage murders of three 8-year-old boys and the conviction of three teenagers accused of killing them as part of a satanic ritual.

10+ pics inside of Reese Witherspoon playing tennis…