Jerry Webster (Hudson) and Carol Templeton (Day) are rival Madison Avenue advertising executives who each dislike each other's methods. After he steals a client out from under her cute little nose, revenge prompts her to infiltrate his secret "VIP" campaign in order to persuade the mystery product's scientist to switch to her firm. Trouble is, the product is phony and the "scientist" is Jerry, who uses all his intelligence and charm to steal her heart in this outrageous comedy of mistaken identity, co-starring the ever-delightful Tony Randall.