Brodien was a CIA agent.
Season 4
Brodien and Sydney were on a surveillance mission in Shanghai when their cover was blown and they were chased by numerous thugs down the city streets. Sydney and Brodien ran into a club rave and locked themselves in the bathroom, trying to figure out how they'd escape the assailants. Over Sydney's radio, Sydney and Brodien could hear their other CIA agent codenamed Shopkeeper getting slain.
Knowing Brodien would die at the hands of the thugs, Sydney remodeled Brodien to look like a punk club member and told him to strut out of the club. Brodien slowly walked his way out of the club and was ignored by the thugs, reaching safety (Authorized Personnel Only, Part 1).
Brodien was later deployed in Russia after a humongous Mueller device was activated in a small city by Elena Derevko. His whole team was slaughtered by The Infected and he was left to fend for himself by his own until Sydney, Vaughn, Jack, Nadia, and Irina showed up via parachuting. He told them about the device and that he tried to stop it numerous times, but all of his attempts failed. He also said once you're infected with the water, there's no changing back. Since all the cars weren't working, they had to walk to the building housing the device. When they got there, Brodien began to unlock the door and Sydney remarked on how his ear wound healed up nicely and Brodien said, "Yeah. And if you uh, plan on putting any more holes in me, just go ahead and tell me now, alright?"
Immediately afterwards, he was stabbed in the chest by an Infected Russian. Before dying, he told Sydney and her team to end the reign of terror (Before The Flood).