Transformers Reaction Force

Transformers Reaction Force, also known as the TRF, is the secondary antagonistic faction-turned-anti-heroes in the 2017 film Transformers: The Last Knight. An international paramilitary force, they are tasked with eradicating on Earth of Transformers (whether Autobot or Decepticon), and any human who sympathizes with them.

At the conclusion of the movie, the TRF ultimately switched sides in order to help Cade Yeager and the Autobots in their fight against Megatron and Quintessa in the planet of Cybertron and the TRF presumably was disbanded after the battle.

Background
The Transformers Reaction Force was created as a paramilitary organization with the same intentions as Cemetery Wind; destroy all Transformers, whether Autobots or Decepticons, hiding on Earth because many Transformers have been coming to Earth for years, which they deem to be an "invasion". They were independent of any national government, but they do they work closely with many of the authorities (particularly that of the United States and United Kingdom) to eradicate Transformers worldwide.

Finding Cade Yeager
One TRF group worked with the U.S. Army was led by Santos with a former NEST member, Colonel William Lennox as a liaison to the military. One day, a group of kids led by Izabella were trespassing upon a damaged area of Chicago and they responded by deploying their TRF Walkers and one of them killed Autobot Canopy as it had been mistakenly identified as a Decepticon.

In the same area, Cade, who had a bounty on him, encountered a dying knight inside the ship that gave him a metallic talisman. After detecting the Decepticon scout Barricade, the group cornered Cade, but he was freed as the Autobots had more firepower. However, a sniper fired a tracker on Bumblebee so they can follow him and his Autobot comrades.

Finding the Staff
Megatron contacted the U.S government, willing to negotiate with them in order to get Cade's Talisman and the Staff. They sent Lennox and a group of lawyers to negotiate the release of several of Megatron's imprisoned soldiers. The Decepticon-TRF alliance proceeded to pursue Cade, his coworker Jimmy, Izabella, Sqweeks, and the Autobots to the nearly abandoned town.

In the ensuing battle, Dreadbot, Onslaught, Mohawk and several TRF soldiers were killed because they were outnumbered and outmatched by the arrival of Dinobots (Grimlock and Slug), forcing Megatron, Nitro Zeus and Barricade to retreat. In England, a combined force of TRF soldiers and MI6 operatives arrive at the mansion to hunt Bumblebee, Hot Rod, Cogman, Cade, Sir Edmund Burton and Viviane Wembly, but failed as the group escaped both of them, as well as Barricade during the chase in London.

Then, they pursued Cade, Viviane, Bumblebee and Cogman with their own submarines until they reached the underwater ship belonging to the Guardian Knights. They had finally found the group and attempted to take Merlin's Staff, only for Viviane to turn the tables against them until a brainwashed Optimus Prime, who had unexpectedly returned to Earth, took it away from Viviane and exited the ship. Then, Cade ordered Bee to follow Prime and Bee did as he was told.

At the surface of the Knights ship, Bee fought Prime until he was overpowered just as Lennox and Cade came to help out, but failed because of the interference from the sea waves and the rising of the Knights ship. Just when Prime nearly stabbed Bee, the mute Autobot scout finally spoke to his long-time Autobot leader and his voice allowed Optimus' true identity to return.

Stopping Quintessa
The TRF had a huge gathering in the field with Cade, Jimmy, Izabella and Sqweeks, as well as the Autobots, as Optimus gave the orders before heading on Cybertron for a big battle. The TRF members led by Santos agreed to work with Cade and Vivian to retrieve the staff, which was being used by Quintessa to harvest Earth's energy for Cybertron's reconstruction. They all tore off their badges after Santos had a conversation with Cade and his final realization that not all of the Transformers are evil.

As soon as they reached the ignition chamber, the former TRF members, U.S. Army and the Autobots fought the Decepticons and the Infernocons outside the ignition chamber. Unfortunately, the troops had taken heavy causalities and they decided to deploy an aerial nuclear strike to bring the chamber down. However, this plan failed as the chamber remained operational even though it started to collapse.

The military led by Lennox and the former TRF members led by Santos watched the collapsing debris of Cybertron, the Autobots were able to reach to the ground, with Vivian and Cade safely sheltered in Optimus' vehicle mode. After a long battle, the Autobots gave their farewells to their old human allies as they returned to Cybertron in order to rebuild it, as well as planet Earth, at the end of the movie TRF was dissolved.