Hill Harper joins Rosario Dawson, Josh Hartnett, Frank Langella, Gena Rowlands, Penn Badgley, Teresa Palmer and Alexis Bledel in the ensemble relationship drama, Parts Per Billion. 

Written and directed by Brian Horiuchi, and produced by AKA/Bow Films, the drama will follow 3 separate couples as they all deal with an event that threatens to destroy their relationships.

It's not yet public what pairs will make up the 3 separate couples, although I'd take a wild guess an say that Harper (assuming he makes up one of the 3 pairs) will likely be partnered up with Dawson, who's also serving as executive producer on the project, by the way, along with Joe Jenckes, Cotty Chubb, Arianne Fraser, D. Todd Shepherd and George Waud. 

Molly Hassell, Jennifer Levine, Michael Benaroya and David Dickson are all producing.

Parts Per Billion is currently shooting in Detroit.