*”CSI: NY” star Hill Harper has joined the cast of “Parts Per Billion,” a drama also starring one of its executive producers Rosario Dawson. The story follows three separate couples as they all deal with an event that threatens to destroy their relationships.

The project also stars “Gossip Girl’s” Penn Badgley, Teresa Palmer, Alexis Bledel, Frank Langella, Gena Rowlands and Josh Hartnett.

Written and directed by Brian Horiuchi, “Parts Per Billion” is currently shooting in Detroit until the end of the year.