Three years after the Rainbow Program's disbandment, a surge in global terrorism from a group called the White Masks prompts its reactivation under a new leader codenamed "Six." She assembles elite operatives from special forces units across multiple nations to confront this threat. After a chemical attack on a university is thwarted, Team Rainbow expands its operations worldwide, recruiting specialists from dozens of countries. Over the following years, leadership changes hands, internal conflicts arise when a private military company called Nighthaven is invited to join, and a rogue former operative named Deimos orchestrates a campaign of violence against Rainbow itself, forcing the team to hunt him down while defending their own existence.