Linley & Patrick Series by Allyson Jeleyne

An alternate cover for this ASIN can be found here.In October 1921, Linley and Patrick set out for a long overdue holiday. But when their train is mysteriously halted in Vienna, Lord and Lady Kyre must abandon their plans for sunshine and gin fizzes to save a nation in need. The glittering cafes of Jazz Age Paris, rolling hills of rural Hungary, and the trip of a lifetime aboard the Orient Express lead Linley and Patrick on an adventure that just might go down in history.