Edinburgh Escape by Elle James

Family Secrets. Deadly Truths. A Romance Forged in Fire.
Preschool teacher Maggie McKendrick never expected a DNA test to lead her to Scotland—or into the sights of a killer. But when an attempt on her life is made en route to meet the half-brother she never knew she had, she calls the only people she can trust: her friend Sadie McClain and her husband Hank Patterson, owner and founder of Brotherhood Protectors.

Enter Callum McCall, a former SAS soldier turned Brotherhood Protector, assigned to keep Maggie safe. Stoic, skilled, and undeniably magnetic, Callum isn’t prepared for the firecracker American who challenges him at every turn.