STX Entertainment and the Jim Henson Company are teaming on an untitled comedy movie combining humans and puppets.

Brian Henson will direct the project, based on a story by Todd Berger and Dee Robertson. Berger wrote the screenplay with revisions by siblings Erich and Jon Hoeber; the story is set in a world where puppets and humans live together.

The plot is centered on the puppet stars of the iconic TV show “The Happytime Gang,” with the family-friendly cast leading lives off-camera that would make a tabloid writer blush. When the stars begin to be mysteriously murdered, two mismatched detectives – a take-no-prisoners human and a hard-drinking puppet — must put aside their differences to stop the killings and catch the culprit.

“The Henson puppets have always had a compelling adult component to them,” Adam Fogelson, chairman of the STX Entertainment Motion Picture Group, told Variety.

Fogelson said the R-rated comedy would be in the vein of such projects as the Henson Co.’s “Puppet Up!” live shows, “Who Framed Roger Rabbit” and “Ted,” which he oversaw while at Universal. He also said production could start before the end of the year, contingent on cast availability.

The Henson Co. has been developing the project since 2008. Variety reported in February that Joseph Gordon-Levitt would produce and star in the live-action “Fraggle Rock” movie for New Regency, the Henson Co. and Lisa Henson.

Year-old STX is on the verge of launching its first films, with “The Gift” opening Aug. 7 and “The Secret in Their Eyes” on Oct. 23.

News about the project was first reported by Deadline.com.