The autumn term is underway, and Lola Vance is reluctantly enduring a ninety-minute school bus ride to Lake Velence for the annual sixth-grade retreat. Accompanied by the boisterous Tommie?who has invented "electricity-free karaoke" using a cheese sandwich named Geoffrey as a prop?and Rae (Réka), who is mathematically calculating the probability of Tommie falling into the aisle, Lola is trying to escape her complicated life . Her mother has begun dating a quiet historian named Gabriel, a structural change that Lola actively resents. Politics hit a peak when room assignments are posted at the Golden Crown Hotel: Room 204 traps Lola, Tommie, and Rae with the elite, front-facing, perfectly packed Bea Wenckheim, who specifically requested them because they are "known quantities" . After a chaotic midnight pseudo-séance that devolves into an improvised rock opera about the hotel housekeeper, the tension between the girls begins to fracture into something resembling a team.
At six o'clock on Saturday morning, unable to sleep due to the thin hotel curtains, Lola and the early-rising Rae slip down to the lake to observe the optical properties of shallow water . Standing on the damp wooden pier surrounded by autumn mist, Lola spots a sharp, metallic rectangular corner protruding from the lakeside mud . Lying flat on the wet boards, she digs her hands into the freezing clay and pulls out a heavily weighted, rusted tin box sealed with crumbling 1970s electrical tape . Lola makes a sophisticated executive decision: they will not open it alone; they will bring it back to share with Tommie and Bea.
Laid out on a hotel towel, the contents of the box reveal a 50-year-old time capsule. Inside are a wooden whistle, dried lavender, and eleven black-and-white photographs from August 1972 showing a tight-knit group of teenagers at the fated Üllői Forest School . Turning over the lead photograph, Lola's heart craters: the names inscribed in elegant cursive include a young eighteen-year-old "Margaret"?her grandmother. A cramped pencil note from "M" reads ominously: "We are putting this in the lake because what we did this summer is going to follow us back to Budapest... Some of us are not going to be allowed to see each other again". But the most shocking item is a hidden, meticulous hand-drawn map by architect Tóth Pál from 1879, showing the hidden blueprints of Ivybridge Academy . Marked with a bold pencil 'X' is Room 17, with a chilling warning in her grandmother's hand: "Room 17. Sealed. Locked since 1893. Do not enter alone".
The operation goes dangerously live at breakfast. Mr. Bartlett approaches their table and quietly warns Lola that he saw her pull the box from the mud. In a private talk on the pier, he drops a bombshell: he isn't a member of any secret meetings, but he knows someone planted the 1893 diary in the staff room, and he commands Lola not to show the box to her grandmother yet . "You need at least one other voice," he says, "or you will spend the rest of your life believing what one person told you in a kitchen when she was sad". He directs them to find the old camp instructor, Mrs. Tamás, who still lives in a nearby white-roofed village house.
