In a famous thought experiment based on the notion of ‘eternal return’, German philosopher Friedrich Nietzsche asked what it would be like to live the same life over and over again, for eternity. Nietzsche’s intention was to set a kind of test that encourages us to consider whether we are living our best life, the life that makes us happiest.

In her novel series On the Calculation of Volume, the first book of which was shortlisted for the 2025 International Booker Prize, Danish writer Solvej Balle provides a similar thought experiment, albeit with an important twist. In hers, we are asked to watch her heroine, Tara Seltzer, an antiquarian bookseller, live a single day again and again. One November 18 morning, Tara wakes up to find that she is living the same day, and that she will continue to live November 18, perhaps forever.