HBO has ordered a fourth and final season of "Tremé." It's just unclear how long that season will be.

As first reported by Dave Walker of the New Orleans Times-Picayune, "Tremé" co-creators David Simon and Eric Overmyer announced at a premiere screening in New Orleans tonight that HBO had given its approval for a fourth season, which would close out the story arc that Simon and Overmyer had planned for the series and its characters.

Simon also explained that this wouldn't be a season the length of the first three, which ran 10, 11 and 10 episodes, respectively, and that HBO executives "fought very hard to give us half a loaf" to finish things.

UPDATE: I emailed Simon to ask for clarification on what "half a loaf" means, and he wrote, "HBO has offered us a lump sum to budget a conclusion to 'Tremé,' and we are trying to figure out how to stretch that amount in the best possible way.  Right now, we are tentatively looking at anywhere between four and six hours of programming, depending on a variety of things.  It's half a loaf, but it represents a sincere effort by Mike Lombardo and Richard Plepler to end the narrative properly.  We'll do the best we can with the story arcs and try to conclude 'Tremé' in a resonant way."

Because the nature of this final half-season doesn't fit the terms of the actors' contracts, the entire cast was free to walk away at this point. The producers spent the past week speaking with each actor, and Simon told the premiere audience, “To a person, they all came back, We’re happy for a chance to finish the story on our own terms.”

It's not an ideal solution, but given the ratings for "Tremé" relative to HBO's other original series, the existence of any kind of fourth season is something to be celebrated.