William Faraday refuses to let his youngest daughter, Evelyn, get married before her older sister, Celia. Celia, who has no interest in getting married, takes pity on Evelyn and her suitor Bobby and pretends to have gotten engaged to Colonel John Smith during a short vacation away from home. To avoid difficulties, she states that Smith has sailed to join the British Field Force in Arabia. When her father receives this news, he consents to Evelyn's marriage.
At Evelyn's insistence, Celia writes a love letter to her fiancé, never intending to send it. She later burns the magazine in which she hid the letter, unaware someone has posted it already. The letter is received by a real Colonel Smith stationed in Arabia. He is amused and curious.
After Evelyn's marriage, Celia publishes a death notice in the London Daily Times for her Colonel Smith. The real Smith decides to pay a visit to Celia, pretending to be a close friend of the deceased bringing some mementos. When he gives them to Celia, she is uncomfortable. She eventually realizes "Colonel Vaughan" is not who he says he is, but over the course of a single night, they fall in love.