Tom Clancy’s The Division: Extremis Malis (Tom Clancy’s The Division: Extremis Malis #2)

Weeks into his pursuit of Mantis-the woman who murdered his partner-Division agent Caleb Dunne arrives in Philadelphia. Teaming up with fellow agent Heather Ward, he gathers clues to Mantis's whereabouts, running afoul of an aggressive militia called The Founders.