In this breathtaking sequel to Everneath (2012), Nikki struggles to rescue her boyfriend, Jack. She could only watch as he sacrificed himself to save her, taking her place in the Tunnels of the Everneath for eternity. Every night, Jack appears in her dreams, lost, confused and wasting away. While his presence gives Nikki hope, it's clear his memory is deteriorating and soon the Everneath will claim him completely. Desperate, Nikki turns to Cole for help and together they make the dangerous journey through the underworld. As the entirety of the Everneath seeks to kill her, Nikki vows to stop at nothing to save Jack!