The boys are back in town. Those muscle bound heroes of The Expendables return with an intriguing story in the new trailer for The Expendables III.

Sylvester Stallone, Jason Statham, Terry Crews, Dolph Lundgren, Jet Li, and Arnold Schwarzenegger will be back as the ultimate mercenary team for hire, The Expendables. They will be not be alone as action stars of the past Antonio Banderas, Wesley Snipes, and Harrison Ford join in on the mayhem. The big villain of the picture will be the Braveheart director and actor Mel Gibson.

The Expendables III will find the team going up against their former co-founder Conrad Stonebanks (Gibson). Stonebanks is out for blood and nobody on The Expendables team is safe, especially those younger members.

The new trailer from distributor Lionsgate teases an Expendables film that might be intriguing for its story instead of relying on the novelty of seeing former action stars united onscreen. The trailer does not withhold its set pieces though, the most prominent being a prison break involving a train and helicopter.

Another change for the franchise is the MPAA rating of PG-13 unlike the previous two installments which were rated R.

Stallone commented on the rating change at Cannes Film Festival saying he wanted the film “to reach as many people as possible.”

Stallone directed the first Expendables with Simon West (Con Air, Tomb Raider) taking over for the sequel. The films earned $275 million and $304 million respectively in the domestic box office.

The third film is helmed by newcomer Patrick Hughes. He will be the youngest director yet (34-years-old) to tackle the action series. Hughes had his feature film debut in 2010 with the critically acclaimed Red Hill. He is scheduled to direct the English remake of Indonesian marital arts action film The Raid.

The new (and last?) film will still have all of our action heroes we know and love, but this time they are promising something more.

The Expendables III opens in theaters on August 18.