Chapter 11:
* The plot thickens: Anne Beddingfield, a young woman unknowingly involved in espionage, becomes increasingly suspicious of the mysterious "Mr. Brown." She discovers a hidden compartment in her trunk, containing a coded message.
* A crucial clue: Anne's friend, Lucy, reveals that "Mr. Brown" is actually a codename for a spy.
* Suspicion and danger: Anne begins to see the world around her with new eyes, recognizing potential spies and enemies.
Chapter 12:
* A fateful encounter: Anne receives a mysterious message urging her to meet at a specific location. There, she encounters "Mr. Brown" and learns about the importance of her role in the operation.
* Secrets revealed: The conversation between Anne and "Mr. Brown" sheds light on a vital piece of information: a coded message hidden within a painting that holds critical intel for the Germans.
* A critical decision: Anne is given a choice - betray the Germans or remain loyal to her country.
Chapter 13:
* Under surveillance: Anne finds herself under constant watch by a suspicious man who she believes is following her. She becomes increasingly anxious about her safety.
* Seeking help: Anne confides in her friend, Lucy, who helps her decipher the coded message hidden within the painting.
* A daring plan: They devise a plan to expose the spy network and deliver the crucial information to the British authorities.
Chapter 14:
* The chase: Anne and Lucy embark on a dangerous mission, trying to avoid the watchful eyes of the enemy spies.
* A close call: Anne narrowly escapes capture, and the tension ratchets up as she realizes the stakes are high.
* A ray of hope: Anne receives a message from a mysterious source that hints at help coming their way.
Chapter 15:
* An unexpected encounter: Anne and Lucy are pursued by a car and find themselves trapped in a dangerous situation.
* A dramatic rescue: Just when hope seems lost, they are saved by a group of unexpected allies, revealing a deeper layer of the spy network.
* The truth unraveled: The identity of one of the spies is revealed, causing a major shift in the narrative and setting the stage for the climax of the story.
These chapters are crucial in the development of the plot, as they introduce the complexities of the spy network, heighten the tension, and propel the protagonists into a thrilling adventure.
Remember, this is a brief summary. To truly appreciate the nuances of the plot and the masterful storytelling of Agatha Christie, you'll have to read the book!