Gregory Peck as a journalist who wants to write a story on antisemitism in post WWII New York. He searches for an "angle," finally deciding that the best way to make a case against antisemitism is to live with it. And so he enlists the help of his employer to hold himself out as Jewish, and calls upon his Jewish army buddy to serve as a sounding board.
Soon his boss' niece, Kathy, enters the picture. A young, urbane divorcee who first suggested the antisemitism piece, she's the only person outside his family and his boss who knows his secret. As the upper-class type, she finds it difficult to plan a wedding or look at homes when all the country clubs and best neighborhoods are "restricted." There's nothing written on paper about the restrictions, of course. It's just a "gentleman's agreement." Peck finds his friends and acquaintances are quite suddenly either absent or overly compensating, trying too hard to "prove" they're not prejudiced. The only person who remains a true friend throughout is the gossip columnist, probably my favorite character and tartly played by Celeste Holm.
Tempers flare throughout as Peck, who is bearing the brunt of the intolerance, can't understand why Kathy won't stand up to what little she has to deal with. When his son is taunted at school, his and Kathy's relationship finally hits the skids.
It takes a visit from Army buddy Dave Goldman to help Kathy to see the light: that not speaking out against subtle antisemitism is the same as condoning it.
It's worth viewing, and is very entertaining.