In the film *Home Alone* (1990), "secrets" range from hidden character backstories and personal motivations to subtle plot points that characters keep from one another (and the audience).
### **1. The McCallister Parents’ Hidden Details**
* **The Discarded Passport:** The most critical "secret" in the movie is one the parents don't even know they have. In the opening scenes, when the pizza spills, Peter McCallister (John Heard) cleans up the mess with napkins and accidentally sweeps Kevin’s plane ticket and passport into the trash. This explains why the headcount error at the airport wasn't caught—there was no "extra" ticket left over to signal a missing child.
* **The Parents' Professions:** While never explicitly stated, director Chris Columbus revealed in later interviews that Kate (Catherine O'Hara) is a **highly successful fashion designer**. This is the "secret" behind the many mannequins in the basement (which Kevin uses for his party) and the family’s extreme wealth. Peter is suggested to be a successful businessman or in advertising.
* **The Missing Dog:** Early in the film, a family member is heard on the phone saying the dog has been put in a kennel. This explains the doggie door that Marv pokes his head through later—a "secret" family member who is never seen on screen.
### **2. Old Man Marley’s True Identity**
* **The "Shovel Slayer" Hoax:** The neighborhood legend that Marley is a serial killer who murdered his family is a secret kept by the neighborhood children (led by Buzz). The reality is that Marley is a lonely, grieving man.
* **The Family Estrangement:** Marley’s "secret" is his estrangement from his son. During the church scene, he reveals that they had a massive argument years ago and haven't spoken since. He goes to the church to watch his granddaughter sing in the choir because he is not "allowed" to see her otherwise—a heartbreaking secret he keeps until Kevin encourages him to reach out.
* **The Symbolic Wound:** Marley has a bleeding wound on his hand for much of the film. As he begins to reconcile with his family (first by talking to Kevin, then by saving him), the wound progressively heals—going from a bloody bandage to a small Band-Aid, and finally disappearing entirely in the final scene when he embraces his son.
### **3. Harry and Marv (The Wet Bandits)**
* **The Calling Card:** Marv’s "secret" hobby is leaving the water running in every house they rob. He calls it their "calling card." Harry hates this because it turns a simple burglary into a high-profile felony (property destruction), but Marv keeps doing it to build their "brand."
* **Harry’s Hatred of Christmas:** In a deleted scene, Harry explains his secret motivation for robbing these specific houses: he has a deep-seated hatred for the commercialization of the holidays. This gives him a more personal, vindictive edge than Marv.
* **Harry’s Marriage:** A subtle visual secret is that Harry is married; a gold wedding ring is clearly visible on his left hand when the tarantula is on his face.
### **4. Kevin McCallister’s Growth**
* **The "Battle Plan" Secret:** Kevin keeps the extent of his defense plan a secret from the audience until the robbery begins. While we see him preparing, the specific locations and mechanics of the traps are revealed as the burglars hit them.
* **Keeping the Secret from the Family:** At the end of the film, when his family returns, Kevin keeps the entire battle a secret. He doesn't tell his mother about the home invasion or the burglars. The only hint left behind is a gold tooth (Harry's) found by his father on the floor, which Peter looks at with confusion—the final "unsolved" secret of the movie.
### **5. Meta/Production "Secrets"**
* **Buzz’s Girlfriend:** The photo of Buzz’s girlfriend is actually a **boy in a wig**. The director felt it would be too cruel to use a real girl’s photo just to call her "ugly."
* **The Fake Movie:** The gangster film Kevin watches, *Angels with Filthy Souls*, is not a real movie. It was filmed specifically for *Home Alone* in one day to serve as a plot device.
* **Uncle Frank’s Malice:** A "secret" known to the production team was that Uncle Frank was originally written to be even more villainous. Deleted scenes showed him being overtly cruel to Kevin and even suggesting that Kevin was a "liability" to the family’s reputation.