Kitty Granger is an undiagnosed autistic sixteen-year-old living in 1960s London. On a whim, she follows an oddly-behaving passenger off the bus and ends up helping two secret agents, Mr. Pryce and Mrs. Singh, take down a group of Russian spies. Impressed by her quick thinking and attention to detail, the agents offer her a job as Mrs. Singh's "assistant" in a spy organization known as the Orchestra.
The Secret Life of Kitty Granger contains examples of:
- "Be Quiet!" Nudge: Kitty and her fellow spy Verity are eating in a restaurant with Spoiled Brat Diana Lowell, the daughter of Nazi sympathizer Henry Lowell, Earl of Chiswick, whom Kitty and Verity are investigating. Diana and her sycophantic friends make fun of a waitress's ordinary, unglamorous clothes. Kitty says, "Oh, I don't know. I think she looks rather-" Verity kicks her under the table, reminding her not to do anything that might antagonize Diana and threaten their cover.
- Bluff the Eavesdropper: Kitty returns to her room at the manor and immediately notices that her things aren't quite where she left them. Thinking her room might be bugged, she tells Verity, "I think I left my handbag at church. Will you walk me down to look for it?" so the two of them can get outside for a private conversation.
- Character Tics: Kitty flicks her fingers and brushes them against her wool skirt to calm herself.
- Concealing Canvas: Lowell has a safe hidden behind a painting in his office.
- Constantly Curious: Kitty. The plot starts because she was curious about why a passenger on the bus seemed to be trying to avoid another passenger and followed him, then was curious about a misaligned brick near a chalk mark on the wall and removed it, then was curious about the film canister inside and took it.
- Covert Group with Mundane Front: Mrs. Singh is an "editor" for the fashion magazine La Mode. Her cover lets her rub shoulders with the rich and powerful. It helps that La Mode is a real magazine staffed mostly by people who have no idea it's a front organization - the only people who know the truth are Mrs. Singh, Kitty, and her other assistant, Verity Chase.
- Dedication: "For anyone who has ever been told that being different is wrong. Differences are good. They make us human."
- Drives Like Crazy: Tommy the mechanic complains that Verity's driving makes his job much harder.
- False Flag Operation: Lowell and Smythe are planning to blow up Parliament and claim it was carried out by the Orchestra as part of a communist uprising.
- Furniture Blockade: Kitty enters the room where Verity is being held and blocks the doorknob with a chair to give herself time to untie Verity and escape through a window.
- Groin Attack: During a fight at Lowell's estate, a guard throws Kitty to the floor. She falls on her back and kicks him hard in the groin.
- Handshake Refusal: Faith, the Orchestra's inventor, reaches out to shake Kitty's hand. Kitty, who Hates Being Touched, is caught off guard and can't force herself to move before Faith retracts her hand.
- Jack Bauer Interrogation Technique: The villains catch Verity as she and Kitty are fleeing from Lowell's secret chamber. She insists she's just a thief, but they don't believe her, so they take her to a room and rough her up. Kitty comes to her rescue before they have time to inflict any serious injuries.
- The Mole: Mr. Pryce's superior, The Old Man, is in league with Lowell and Smythe.
- Named After Somebody Famous: Diana was named after Diana Mitford
. Mitford's husband was Oswald Mosley, who in the story is an old friend of Diana's godfather Richard Smythe, another extremist. - Punk in the Trunk: The Russians catch Kitty with the film canister and lock her into the trunk of a car to be transported to the warehouse where they interrogate her.
- Secret Underground Passage: The Orchestra strongly suspect that there's a Secret Room in Lowell's estate. Kitty is sent along with Verity to help look for it. Sure enough, she finds a hidden door in the wine cellar that opens into a passageway that leads to a chamber where Lowell, Smythe, and their cronies plot their takeover.
- Sensory Overload: The same sensitivity that makes Kitty good at spotting subtle details and changes in her environment also causes her to be regularly distracted and overwhelmed by colors and sounds.
- Shoe Phone: The spies use tape recorders disguised as pens.
- This Is Reality: While Kitty is struggling with the fact that she shot someone to protect herself and Verity: "In the films, spies drank martinis, and shot people without remorse, and had a clever retort for every occasion. Real life wasn't like the films."
- Tragic Dropout: Kitty would have preferred to stay in school, but after her mum died, she had to help her Struggling Single Father in his store. She persuades him to let her work for Mrs. Singh by telling him that she'll be paid enough for him to hire someone to replace her.
- Use Your Head: Kitty thrashes around while the Russians try to pin her to a chair. She manages to headbutt one of them in the face hard enough to make him scream in pain. She does the same thing while fighting with the Nazis at Lowell's estate.
- Working Out Their Emotions: Kitty has felt for years like there was a coiled spring inside her that grows tighter with each moment of stress. When she joins the Orchestra, she begins her training with several weeks of intense exercise, which exhausts her body but makes the spring inside her feel looser and looser. By the time she starts martial arts training, she feels better than she has in her life, and her superiors are impressed by her boundless energy.
- You Have Outlived Your Usefulness: When the Russian spies realize that Kitty has followed one of them, the boss gives the order to dispose of the compromised spy she followed, saying, "Our friend at the Ministry of Defense has outlived his usefulness." The spies are captured before they can carry out the order.
