No Peace for the Wicked

From amazon.com: "Antonia Winfield sensed someone was following her. She'd seen a man in a brown suit. He was even behind her in the travel agents where she'd booked her holiday abroad. But perhaps she'd just imagined things. This year she was going on a restful, comfortable trip to a lovely Greek island - but that's not the way things turned out. Mrs Winfield's niece was going on the trip with her, and the two ladies soon had a third companion: the man in the brown suit . . ."