Both Nicky Ferrante (Cary Grant) and Terry McKay (Deborah Kerr) are in serious relationships they are trying to convince themselves is love. Then both find themselves on a trans-Atlantic voyage without their future mates. Nicky meets Terry and there is immediate attraction. But even knowing that they are meant for each other, they do their best to not get romantically involved until they can reach their destination and get out of their committed relationships. So convinced that they should both be with each other, they decide to meet atop the Empire State Building in six months to give them time to get out of their other relationships. Both are able to break up and know that it is for the best. But when they try to meet each other, there is a misunderstanding and both think that the other person has decided to not pursue a relationship--that their sparks on the ship was just a passing fling. Tension mounts as the meet one last time and still don't know that the other person really wants to be with them.