American heiress Louise Vandermeer has agreed to marry a European aristocrat. Her intended is rumored to be a hideously ugly man, a prospect that propels her into a reckless shipboard affair with a compelling stranger she never sees in the light of day. Unbeknownst to Louise, her mystery man is actually her betrothed, Charles d'Harcourt, whose romantic prank backfires when he becomes smitten with his own fiancee.