Marina, after sneaking home late, is blackmailed by her sister Natalia to do her math homework to keep her secret from their strict Aunt Ursula. Caught eating honey cakes meant for sale, Aunt Ursula threatens to send Marina and her sisters to foster care. Their uncle Ivan unexpectedly arrives, revealing he's been financially supporting them and takes them away to live with him. Life improves until Uncle Ivan plays dead as a prank, then offers a million dollars to one sister, causing rivalry. Marina discovers a key behind a painting, leading to a music box with a cryptic note about their mother's birthday. Natalia fakes pregnancy to scare off her boyfriend Petrov, who was also Marina's crush. Marina solves the riddle, finding the money in a safe. Uncle Ivan reveals it was all a test; impressed by Marina's intention to share the money, he rewards all three sisters.
Here are the key facts from the text:
1. The narrator, Marina, lives with her two sisters, Natalia and Tanya, and their aunt, Ursula.
2. Marina's parents passed away in an accident a few years ago.
3. Marina's uncle, Ivan, takes the sisters to live with him in his old mansion.
4. Uncle Ivan has a large sum of money, $1 million, that he wants to give to one of his nieces.
5. Uncle Ivan sets up a challenge for the sisters to figure out who will receive the money.
6. Marina finds a key hidden behind a painting in Uncle Ivan's study.
7. The key is later found to fit a music box with a small compartment containing a note with numbers.
8. The numbers are revealed to be the combination to a safe in a mysterious room in the eastern wing of the house.
9. Inside the safe, Marina finds stacks of money, which she initially thinks is the $1 million.
10. Uncle Ivan returns and reveals that he was testing the sisters to see how they would work together.
11. Marina decides to share the money with her sisters, despite being offered the full amount herself.
12. Uncle Ivan praises Marina for her decision, saying that she knows what family is all about.
13. The story ends with the sisters planning to divide the money and go shopping together.