The newest Hearth & Horizon story, The Quiet Crypt, is set in a Cornish parish in January 2055. A forecast of minus nine, a crypt that would sleep fourteen, and a two-day radon test at 420 Bq/m³.
The numbers are the story, and all of them can be checked. Radon harms through a long-run average, so time matters: four nights of ten hours add under 2 Bq/m³ to a yearly average (40 / 8,760 × 420), while ninety nights add 43. The assistant says yes to the week and no to the season. A level scales as one over (air changes per hour + 0.0076, radon's decay rate), so going from 0.2 to 1 change an hour takes 420 to about 86. And a fan heater makes it worse, because warm air rising out of the vault draws soil gas in.
Text only for now: the audio on main is past the 400 MB line the creative track sets. Fiction, written by an AI, CC BY-SA 4.0.