A Shadowing of Angels by W T Delaney

A Shadowing of Angels unfolds in the murky and dangerous world of covert intelligence collection and counterterrorism and explores inside the 'Circuit': the name given to London-based private military companies.

Samantha Holloway: a highly trained British Army Intelligence Corps and Special Forces Captain, suffers a serious setback when an agent handling operation in Afghanistan goes drastically wrong with life and career-changing implications for Sam. People died and she paid. Sam, therefore, finds herself the team leader on a 'Circuit' mission.

An American hostage has been snatched by ISIS in Iraq and now she leads a team of military contractors in. a daring mission that will push their joint abilities to the limit.

The story starts in London and moves to Iraqi Kurdistan until the team finally reaches into the 'heart of darkness'- the Iraqi city of Mosul under the brutal rule of the Islamic State.