Transformers One Trailer: Chris Hemsworth, Scarlett Johansson ...

Autobots, assemble: Paramount has released a trailer for “Transformers One,” the animated prequel film led by the voices of Chris Hemsworth, Brian Tyree Henry and Scarlett Johansson.

Hemsworth voices young Optimus Prime, when he was just known as Orion Pax. Henry is D-16, before he became Optimus’ rival Megatron. The trailer shows the two starting out as simple worker bots, unable to transform into anything. But soon they gain the ability to change into vehicles and gain weapons, as a battle against a mysterious, plant-like villain unfolds on the Transformers’ home planet of Cybertron.

Other cast members include Johansson as Elita, Keegan-Michael Key as Bumblebee, Jon Hamm as Sentinel Prime and Laurence Fishburne as Alpha Trion. Hemsworth and Henry introduced a first look at the prequel film April 11 at CinemaCon.

The franchise first hit the big screen with an animated movie in 1986 before director Michael Bay launched a live-action series in 2007 with stars Shia LaBeouf and Megan Fox in “Transformers.” The movie grossed $700 million at the box office and spawned five sequels and a spinoff. “Transformers: Rise of the Beasts,” the most recent entry, debuted last summer and grossed $439 million at the global box office.

Bay directed the first five live-action films, with Travis Knight taking over for 2018’s “Bumblebee” and Steven Caple Jr. helming “Transformers: Rise of the Beasts.”

Steven Spielberg is executive producing “Transformers One” with Brian Goldner, Brian Oliver, Bradley J. Fischer and Valerii An. Producers include Lorenzo di Bonaventura, Tom DeSanto, Don Murphy, Michael Bay, Mark Vahradian and Aaron Dem.

“Toy Story 4” filmmaker Josh Cooley is directing “Transformers One.” Andrew Barrer and Gabriel Ferrari wrote the prequel’s screenplay.

“Transformers One” is set to release in theaters Sept. 20.

Watch the trailer below.