Nancy (Lake Bell) is a 34-year-old female journalist. One day, on the train, Nancy met a girl who left a book in her hand to Nancy. This book was a connection code between the girl and her blind date. After the train arrived, Nancy wanted to return the book to the girl, but the girl had already disappeared. Just as Nancy was wandering under the big clock of Waterloo Station in London with a book in hand, a man named Jack (Simon Pegg) called Nancy. He had a book exactly like Nancy in his hand. It turned out that Jack mistakenly thought Nancy was his blind date. In this way, in a mistaken collision, Nancy and Jack began to interact. Can this relationship, which was opened by a misunderstanding, go to the end smoothly?