'24: Live Another Day': Jack Bauer's 8 Biggest and Bloodiest Moments

From a knife to the neck to a game of Russian roulette, if there is a grisly way to kill, maim or torture a suspect, Kiefer Sutherland's character has tried it.

To celebrate the anxiously anticipated return of Fox's most gripping drama with the 12-episode event series 24: Live Another Day, The Hollywood Reporter looked back at some of Jack Bauer's biggest and most brutal moments since the series premiered in November 2001.

Over the years, the Counter Terrorist Unit's most proficient agent has shot, stabbed, suffocated and even bitten his enemies while attempting to ward off terrorism plots, presidential assassinations and threats to his family and loved ones.

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1. Jack kills a militia member under FBI protection and delivers his head to a former gang member

Season two, 8 a.m.-9 a.m.

Former militia member Marshall Goren came to a very messy demise despite being in the FBI's witness protection program. While he was being held in downtown Los Angeles, Jack first shot Goren then went to extreme measures after deciding he needed his severed head to establish cover with a terrorist organization. "I'm gonna need a hacksaw," he growled.

2. Jack kills a guy with a flare gun

Season two, 4 p.m.-5 p.m.

Known as one of Bauer's best kills -- as well as spawning one of his cheesiest lines -- Jack tapped his inner Arnold Schwarzenegger when he blew a Coral Snake mercenary away with a flare gun, telling him: "You're fired!"

3. Jack develops a heroin addiction

Season three

Even Bauer wasn't immune to the temptations of heroin when he went undercover with a gang run by Mexican drug lord Ramon Salazar. Jack took heroin to maintain his cover and got hooked, but going cold turkey to battle his addiction still didn't slow down his efforts to stop the sale of the Cordilla virus and keep daughter Kim (Elisha Cuthbert) out of danger.

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4. Jack executes Ryan Chappelle

Season three, 6 a.m.-7 a.m.

In one of the most chilling moments of the season, Jack executed his boss, CTU director Ryan Chappelle on the direction of the president to save the world from a deadly biological virus attack.

5. Jack plays Russian roulette in a prison

Season three, 5 p.m.-6 p.m.

Infiltrating a prison was just the first challenge for Jack, who was then forced to play a few rounds of Russian roulette, first with a prison guard (he lost immediately) and then with Salazar. Not knowing whether the gun was loaded when it came to his turn, Bauer calmly pulled the trigger the first time and had a lucky escape, and on his second go he flipped the gun around and shot Peel, the prisoner who had forced him to play.

6. Jack tortures Paul Raines with a wire

Season four

Being his girlfriend Audrey's ex-husband could have been motivation enough for Bauer to electrocute Paul Raines with a wire, and finding his name on the lease of a building used by terrorists was even more incentive (however, Paul went on to cooperate with Jack).

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7. Jack breaks in to the Chinese consulate

Season four, 2 a.m.-3 a.m.

Breaking international law and countless CTU rules, Bauer went rogue and conducted a raid on a Chinese consulate to extract Lee Jong, whom he believed knew how to reprogram a nuclear detonator, resulting in a shoot-out that led to Paul Raines' death.

8. Jack knifes an enemy soldier in the neck

Season four, 7 p.m.-8 p.m.

Bauer got up close and personal when he killed Specter (the leader of a mercenary group played by Christopher B. Duncan) by stabbing him in the neck with a Microtech Halo 3 knife while he was hiding out in a clothing store.