A mother's love can be deafening . . .

Isaac is Hannah’s entire world. She knows that her son is gifted, and that those gifts make him vulnerable. To keep him safe, she spends every waking moment by his side. If she lets her guard down, lets him out of her sight, lets him show what he’s capable of, he will be taken from her.

When the Soundfield arrived twenty years ago, the world changed with it. Now, people are forced to live at night due to the deadly heat of the day, food and water are scarce, and everyday life is punctuated by the constant and disconcerting hum from the Field. A brilliant scientist, Hannah spent her early career working on the enigma of the Soundfield, looking for answers; now, resigned, she has focussed all her energies on keeping Isaac living, not just alive.

To do so, she will have to lie to the people she knows and hope she can trust the ones she doesn't. Because the only thing more dangerous than her lies, is the truth of what she has done.

This book constitutes the refereed proceedings of the 15th Conference on Computability in Europe, CiE 2019, held in Durham, UK, in July 2019. The 20 revised full papers presented were carefully reviewed and selected from 35 submissions. In addition, this volume includes 7 invited papers. The conference CiE 2018 had the following six special sessions: computational neuroscience, history and philosophy of computing, lowness notions in computability, probabilistic programming and higher-order computation, smoothed and probabilistic analysis of algorithms, and transnite computations.