The story centers on the Townsend Agency, which has expanded globally with multiple teams of Angels guided by multiple Bosleys taking on high-stakes missions around the world. When a systems engineer blows the whistle on dangerous technology, the Angels are called into action, putting their lives on the line to protect society. The technology in question is a revolutionary clean energy device named Calisto, which has the potential to revolutionize the way humans use power but also contains the dangerous possibility of being weaponized.

As the engineer, Elena Houghlin, becomes the target of assassins, she is brought into the fold by the Angels. Under the mentorship of a senior Bosley, the team of three embarks on a breakneck mission that spans from the executive offices of Hamburg to the parties of Istanbul. The Angels must use their unparalleled combat skills and espionage prowess to prevent the nefarious use of Calisto while confronting and untangling a web of corruption that tests their strength as a team.