Hanover Street (1979)

Synopsis
In this WWII romance, Harrison Ford (face-to-face with superstardom from his involvement in Star Wars) is cast as David Halloran, an American bomber pilot stationed in London. During an air raid, Halloran meets and falls in love with beautiful Briton Margaret Sellinger (Lesley-Anne Down). Naturally, Margaret is married, and just as naturally David hopes that this won't make too much difference in their relationship. But this is not to be: Halloran is assigned behind enemy lines on a dangerous assignment, and his partner in this endeavor is Margaret's husband, Paul (Christopher Plummer). ~ Hal Erickson, All Movie Guide