A Theory of Dreaming: Sequel to A Study in Drowning

Return to the immersive, lush, and dreamlike world of the instantly bestselling dark academia fantasy A Study in Drowning as the aftermath of their first discovery pulls Effy and Preston on a final adventure and brings their haunting love story to its end in this stunning sequel and final book in the duology.

All stories come to an end.

Effy learned that when she defeated the Fairy King. Even though she may never know exactly what happened at Hiraeth, she is free of her nightmares and is able to pen a thesis with Preston on the beloved national fairy tale Angharad. She has finally earned a spot at the literature college, making her the first woman in history to enroll.

But some dreams are dangerous, especially when they come true. The entire university—and soon the entire nation—is waiting for her to fail. With the Fairy King defeated and Myrddin’s legacy exposed, Effy can no longer escape into fantasy. Who is she without her stories?

With Effy under threat, Preston is surprised to discover a rage simmering inside him, ringing in his ears like bells. He begins to dream of a palace under the sea, a world where he is king—visions that start to follow him even in waking.

As the war between Llyr and Argant explodes, Effy and Preston find themselves caught in the crossfire: Effy losing her dreams and Preston losing himself in his.

Are dreams ever truly just dreams?

© 2025 HarperCollins (Audiobook): 9780063421714

Release date

Audiobook: 29 July 2025