The most buzzy network pilot now has an official greenlight: Fox’s Batman prequel Gotham is a firm go (first trailer here).

Fox announced the decision Monday as the broadcast networks head into their busiest deal-making week of the year. The network upfront presentations to advertisers start in seven days. Most of the decisions whether to renew and cancel bubble shows, as well as which pilots are getting series orders, will be made this week. Gotham stars Ben McKenzie (Southland) as a young detective James Gordon (first photo) who battles an assortment of emerging villains in Gotham City. We’re told Fox’s order is for “at least” 13 episodes.

For Gotham, odds were always stacked in its favor. A live-action Batman-universe TV show will have huge awareness and a potential built-in audience. Plus, the script by The Mentalist and Rome creator Bruno Heller was very strong. You may have read earlier references online to Gotham already having a series order — it was technically a pilot order with a “series commitment,” which means Fox would have to pay a penalty if they didn’t go to series, but it wasn’t a sure thing. We’re hearing Fox’s other pickups will be made within the next couple days and we’ll have plenty of coverage of Gotham throughout the next week.

The big challenge for Fox is marketing a Batman show that doesn’t have Batman — in Gotham, Bruce Wayne is about 12 years old. ABC faced a similar challenge with this season’s Marvel’s Agents of SHIELD, a superhero show where the familiar heroes were offstage. There will be plenty of villains on board, however, with origin-story versions of The Riddler, The Penguin and Catwoman all on board.

Also, more Gotham scoop: We’re hearing there is a Gotham first trailer debuting tonight during the return of Fox’s 24: Live Another Day — as if you needed another reason to watch Jack Bauer’s return. This is very unusual — an on-air trailer for a new fall show before the broadcast upfronts? But Fox wants to go heavy on Gotham and sees the 24 reboot as a strong vehicle to launch a marketing campaign for the show.