This time, it's personal.
When American covert operative Chase Fulton and his team of battle-hardened warriors lose one of their own in an unthinkable and unprovoked act of vengeance, there's no limit to the wrath they will unleash on their shadowy attacker to make him pay the ultimate price for his unforgivable sin.
Unlike the sanctioned assignments in the past for tactical Team 21, when global interests conspire to eliminate every member of the team, one by one, the rules of engagement crumble, and only one simple directive remains: eliminate the threat with limitless force until no enemy with breath in his chest remains. The team must forge themselves into the deadliest iron they can become, to face the unyielding enemy, before everything and everyone they love is destroyed. Finding the strength to defeat an invisible enemy, they are forced to reach deep inside their souls and unearth a fire like none they've ever stoked, to burn hotter and longer and higher than the bloodlust of their foe. The threat must be crushed and ground into oblivion if the team is to survive and preserve everything they hold dear, but is the enemy too vast, too strong, and too driven? Step inside a world of loathing and ultimate darkness to feel the fury and taste the anguish as Chase and his team fight for their lives in what could be their final battle.