Betrayalthe - Olivia Sinclair Series (1)

"Catherine Carlisle is trapped in a loveless marriage and the threat of World War Two is looming. She sees no way out ... that is until a trusted friend asks her to switch her husband's papers in a desperate bid to confuse the Germans. Soon Catherine finds herself caught up in a deadly mixture of espionage and murder. Someone is selling secrets to the other side, and the evidence seems to point right at her."--Amazon