Silence In The Threshold. The Black Circuit Series, #2

Lucan left his life as a deadly operative far behind, choosing instead to build a peaceful home with Vexa in a secluded cottage. But when a routine coastal investigation exposes a dark web of corporate crime, their safe haven quickly becomes a trap. The discovery of a familiar, forbidden face within the syndicate's inner circle shatters their fragile reality, raising a terrifying question: will this shocking revelation tear them apart, or will it bring them closer together?With enemies closing in from the shadows and trust wearing thin, Lucan and Vexa realize their danger was no accident at all.
Now, they must decide whether to run again or fight back. To protect the woman he loves, Lucan is forced to awaken the weapon he swore he would never be again, plunging into a brutal war to destroy the hidden mastermind before time runs out.