An unidentified Russian plane lands on German soil where the pilot is picked up by American authorities. To everyone's surprise, the pilot turns out to be a woman - Vinka Kovelenko (Katharine Hepburn) - a very attractive heroine of her country. She claims that in a rage, she took off with no idea of her destination, a story which the authorities are very sceptical about. They assign Captain Chuck Lockwood (Bob Hope) to find out more about her, and although he is at first in hot pursuit of someone else, the two fall in love. This does not mean, however, that he ceases to suspect her of being a spy.