Crossbones

"This is gonna hurt. There are no prisoners with HYDRA, only order. And order only comes through pain. Are you ready for yours?" "Man, shut the hell up!"

- Brock Rumlow and Sam Wilson

Brock Rumlow was a HYDRA sleeper agent inside S.H.I.E.L.D. and the STRIKE team leader. He is a world-class hand-to-hand combatant with an extensive experience in street fighting techniques, various martial arts and military combat techniques.

Agent of S.H.I.E.L.D.
Brock Rumlow was an agent of S.H.I.E.L.D. who, over time, was tasked with leading STRIKE. As the leader of STRIKE team, he often partnered with Captain America and Black Widow after the former joined S.H.I.E.L.D.. During his career, he became a double agent for HYDRA, a terrorist organization with the goal to create the fascist New World Order.

Zodiac
One operation saw Rumlow assisting in the recovery of the stolen Zodiac weapon and the apprehension of the terrorists that stole it.

During one of their missions together, Rumlow, partnered with Rogers and Romanoff, was able to stop a terrorist group led by a man only known as Baker from launching an attack with the stolen Zodiac weapon in Chicago.

Rogers and Rumlow defeated most of the terrorists while Romanoff took care of Baker himself. She was not able to defeat him; however, after his men had fallen, he could not defeat the three of them, so Baker tried to flee by throwing himself from a window.

As Captain America was unwilling to let Baker escape with the Zodiac, he too jumped off the Skydeck and struggled with Baker in mid-air. Unwilling to die in the fall, Baker released the Zodiac to Rogers and activated his parachute, while Rumlow snared Captain America in mid-air back on the Skydeck with a grappler arrow.

Retaking the Lemurian Star
"Thanks." "Yeah, you seemed pretty helpless without me."

- Captain America and Brock Rumlow

Agent Rumlow led STRIKE, Captain America, and Black Widow on a mission to recapture the Lemurian Star, a S.H.I.E.L.D. ship hijacked by Georges Batroc and his pirates. Once Rumlow had debriefed the team on the details of the plan, Rogers left the Quinjet first, when Jack Rollins questioned if he had jumped out without a parachute, Rumlow confirmed that he had. Rumlow and STRIKE team joined Rogers moments later, with Rumlow shooting a pirate who had Rogers at gunpoint. Rumlow and Rollins made their way through the ship, taking a key position outside the kitchen where the hostages were being held. Once Rogers and Natasha Romanoff were in position, they killed Batroc's subordinates and rescued the hostages, including Jasper Sitwell. While Rumlow made his way off the ship, Rogers battled Georges Batroc who eventually escaped.

The Death of Nick Fury
"Captain, they want you back at S.H.I.E.L.D." "Yeah, give me a second." "They want you now."

- Brock Rumlow and Steve Rogers

Rumlow accompanied STRIKE to the hospital when Director Nick Fury was shot and killed by a mysterious assassin. When he received a call from the Triskelion, Rumlow informed Steve Rogers that he needed to return to S.H.I.E.L.D. to debrief with Alexander Pierce. Rogers initially delayed as he was speaking to Natasha Romanoff, but Rumlow insisted that they had to leave immediately. Rumlow and the STRIKE team accompanied him back to the Triskelion.

Chase of Captain America
"Whoa, big guy, I just want you to know, this isn't personal!" "It kinda feels personal."

- Brock Rumlow and Captain America

Rogers' meeting with Alexander Pierce resulted in Rogers being declared an enemy of S.H.I.E.L.D. by Pierce due to having key information about the death of Fury which could endanger HYDRA's secrets. Rumlow and the STRIKE team attempted to capture Steve Rogers inside an elevator, Rumlow spoke to Rogers to gain his trust, noting that he had been sorry to hear about the death of Nick Fury. However, Rogers soon became suspicious and gave the team a chance to escape; they refused and attempted to capture Rogers using Magnetic Handcuffs. After a brief fight, Rumlow and Rogers were the last men standing. Rumlow told Rogers the fight was not personal and attacked Rogers with his Taser Rods. Although he was able to momentarily gain the upper hand, Rumlow was quickly defeated when Captain America knocked him out by picking him on and throwing him against the roof of the elevator before escaping from the Triskelion. Rumlow led the ensuing manhunt against Rogers under the orders of Alexander Pierce and Jasper Sitwell. HYDRA was able to track him to a mall in Washington, D.C. when he and Natasha Romanoff activated a flash drive with a tracker on it. Rumlow arrived at the mall with a his STRIKE Team including Jack Rollins, all eager to gain revenge of their defeat in the elevator, but despite a long search, they failed to spot the fugitives.

Calling the Winter Soldier
"Call in the asset."

- Brock Rumlow

Later, Steve Rogers and Natasha Romanoff were located at Camp Lehigh, where Arnim Zola's computer hard-drive was located. Alexander Pierce destroyed the camp with a missile in an attempt the kill them. Rumlow explored the area, looking through the rubble for their corpses and discovered a pair of footprints, telling him that Rogers and Romanoff had survived and escaped. Rumlow reported back to base and told them to call in the Winter Soldier.

Capture of Captain America
"Three holes, start digging."

- Brock Rumlow

Rumlow and STRIKE captured Captain America, together with Black Widow and Falcon on the streets of Washington, D.C. after they had a prolonged fight with the Winter Soldier. When Jack Rollins attempted to execute Rogers by shooting him in the back of his head, Rumlow noticed a news helicopter watching overhead and ordered him to stop. Then, he took them to a secure location to execute them, only to find that they had escaped with help from Maria Hill. Rumlow and Jack Rollins escorted Alexander Pierce to the HYDRA Bank Facility to begin questioning the Winter Soldier, who was struggling to understand why he seemed to remember Captain America from a past life. Rumlow acted as Pierce's bodyguard as he began questioning the Winter Soldier; Rumlow protected his boss by raising his gun when the Winter Soldier began to attack the people around him. Rumlow watched closely as the Winter Soldier was beaten and Pierce ordered his memories to be wiped once again so he could attack Rogers once again.

Battle at the Triskelion
"You're out of your depth kid!"

- Brock Rumlow to Sam Wilson

Rumlow made his way into the control center of the Triskelion to ensure the launch of the Helicarriers while Captain America revealed HYDRA's infiltration within S.H.I.E.L.D.. When Cameron Klein the technician in control of the launch sequence, refused to send up the Helicarriers, Rumlow threatened to kill him. Sharon Carter defended Klein by putting a gun to Rumlow's head. A gunfight between S.H.I.E.L.D. and HYDRA agents ensued, but Rumlow was able to get the Helicarriers in the air and escape. On his way through the Triskelion, Rumlow managed to kill several S.H.I.E.L.D. agents until he received a call informing him that Black Widow had attacked and captured Alexander Pierce. As he went to protect Pierce, Rumlow was cornered and attacked by Sam Wilson. Rumlow prepared for a long fight and told him that the fight was going to hurt as HYDRA did not take prisoners. Wilson simply told him to shut up as they began to fight. As Rumlow gained the upper hand, he threw his opponent across the room while taunting him that he was out of his depth fighting HYDRA, but while doing this he did not spot the incoming Helicarrier until it was too late and it crashed into the side of the building. Rumlow attempted to flee but was soon knocked over and crushed by the crumbling building. Rumlow managed to survive despite being burned and crushed under Helicarrier rubble, gaining horrific facial and body scars, and was taken away by medics.

Personality
Rumlow was extremely loyal to HYDRA, as well as being slightly cocky, as when he saved Captain America aboard the Lemurian Star. He had a strong attitude, as well as a tendency to go to extreme lengths to do things, as when he threatened to kill Cameron Klein if he did not launch the Insight Helicarriers.

Abilities

 * Master Martial Artist: Rumlow is a formidable hand to hand combatant. He was able to evade the knifes thrown by one of the men in Baker's terrorist cell and easily defeat him, and to hold his own against Steve Rogers for the longest when the whole STRIKE team tried to capture him in one of the elevators in the Triskelion. He also dominated Sam Wilson in their fight and mocked him for being in a superior fighting level, as Wilson only hit Rumlow when he ambushed him.
 * Expert Marksman: Rumlow is a very accurate marksman skilled in sharpshooting, being able to, among other things, shoot a rope with a crossbow to catch Captain America to prevent him from falling from a building, or accurately land a single shot to a target's head while parachuting.

Weapons

 * Taser Rod: While attempting to capture Captain America, Rumlow and his STRIKE team used Taser Rods to weaken the super soldier and arrest him. However they quickly learned that the Rods were not strong enough to stop Captain Rogers and he escaped.

Allies

 * HYDRA
 * Alexander Pierce † - Leader
 * Jasper Sitwell †
 * STRIKE
 * Jack Rollins - Subordinate

Enemies

 * S.H.I.E.L.D. (First Incarnation)
 * Nick Fury - Former Director
 * Maria Hill - Former Deputy Director
 * Sharon Carter - Former Colleague
 * Steve Rogers/Captain America - Former Colleague turned Enemy
 * Natasha Romanoff/Black Widow - Former Colleague turned Enemy
 * Cameron Klein - Former Colleague turned Hostage
 * Baker
 * Georges Batroc
 * Sam Wilson/Falcon

Trivia

 * In the comics, Brock Rumlow is an agent of the Red Skull known as Crossbones, and became romantically involved with his daughter Sin. It has been confirmed that he will bear the moniker of Crossbones in Captain America: Civil War.
 * In Captain America: The Winter Soldier, Brock Rumlow wears equipment under his Bulletproof Vest that is meant as a reference to his attire in the comics.