Deeplight is a young adult fantasy novel by Frances Hardinge, published October 31, 2019 by Macmillan Children's Books.

30 years before the events of the book, the gods all turned on each other and tore each other apart in a disaster known as the Cataclysm, and the remnants of their bodies are now used as high durability material called 'godware' for various purposes.

In an accident involving a stolen bathysphere, Jelt seemingly drowns but comes back to life when a submerged ball of godware reanimates his body and heals his wounds.

However, Hark soon discovers that prolonged exposure to the ball affects your body in strange ways, and is worried about its effect on Jelt, who never leaves its presence.

In a final altercation, Hark reconcile that Jelt drowned in the bathysphere accident, being only kept alive since by the power of the god's heart.