Christie creates tension through her plot. When hardworking Alix comes into some money and independence, she expects to marry Dick, her boyfriend of eleven years. Yet she ends up being swept off her feet in a week by another man, Gerald Martin, and marrying him. From the start, we have to be suspicious about the motives of the other man: why does he suddenly pursue her after she inherits money?

More mystery and tension arise as Alix has a recurrent dream of Dick murdering her new husband:

She saw her husband lying dead and Dick Windyford standing over him, and she knew clearly and distinctly that his was the hand which had dealt the fatal blow.

This acts as a premonition or foreshadowing that a murder is about to occur.

Our sense of foreboding increases when we learn that Gerald has found the perfect cottage. It is in a remote location, and Alix has to cash in half her inheritance so they can afford it. The tension ratchets up even higher when the gardener, George, shows up unexpectedly and wishes her well on her trip to "Lunnon" (London) the next day. Alix denies such a journey is to happen. George also insists the price of the cottage was 2,000, not the 3,000 Alix was told it cost. When Alix finds Gerald's pocket diary dropped in the garden and sees the words "9 pm" written in it for that day's entry, she becomes worried. What is supposed to happen at that time? It occurs to her how little she knows about Gerard.

At this point, the reader is full engaged in the story, sharing Alix's anxiety about what is to happen next.