In their first writing collaboration since creating Gossip Girl nine years ago, producing partners Josh Schwartz and Stephanie Savage are set to write and executive produce The Party, a drama project for ABC and ABC Studios.

Like Gossip Girl, which was based on young-adult books, The Party is an adaptation of an existing property, a Brazilian TV format from Grupo Globo. I hear the network went after the project aggressively, taking if off the market with a pre-emptive buy.

The Party is described as a twisted family drama that follows a murder investigation told over the course of 24 hours. The case begins at a celebration that is interrupted when a body is found floating in the pool. Through flashbacks, the mystery paints every guest as a possible suspect.

Schwartz and Savage will executive produce through their ABC Studios-based Fake Empire. The company’s executive Lis Rowinski will co-executive produce.

abclogoThe Party joins another high-profile sale for Fake Empire this season — one-hour supernatural dramedy Horrorstör, which has a put pilot commitment at Fox. The project, written by Schwartz and Black List screenwriter Michael Vukadinovich based on the novel by Grady Hendrix, is executive produced by Schwartz, Savage, Charlie Kaufman and the Jackal Group’s Gail Berman. Fake Empire’s most recent series include summer ABC event drama The Astronaut Wives Club, which was written by Savage, and the CW’s Hart Of Dixie, which ended its four-season run in May.

Schwartz also created Fox’s breakout The O.C. and co-created with Chris Fedak NBC’s cult hit Chuck. On the feature side, through their overall deal with Universal Pictures, Schwartz and Savage are adapting and producing tentpole Monster High, based on Mattel’s billion dollar franchise.

Schwartz, Savage and Fake Empire are repped by WME and attorney Joel McKuin. Grupo Globo also is with WME and Myman Greenspan.