Fellside by M.R. Carey

Fellside is another terrifying, yet gripping story by M.R. Carey, the author of The Girl With All The Gifts. 

Jess Moulson goes on a hunger strike shortly before entering a maximum security prison, Fellside. 

Though Jess nearly dies, a young boy gives her a reason to live. Alex, the ghost of the boy whom everyone believes she killed, asks her to do the one thing she cannot refuse.

Fellside is a ghost story that reads like a riveting psychological thriller and suspenseful mystery.

Jess's relationship with Alex is complicated. She wants to protect him from everything but he is also powerful. He saved her when a nurse punctured her artery instead of her vein:

"He'd brought her back from the abyss, from the mouth of the grave. She owed him everything and he owed her nothing except arguably a life for a life and a tooth for a tooth."

  
Alex knows, however, that the fire Jess started while she was high hadn't killed him. 

The fire she set hadn't killed him because he was already dead. So who hurt him and how did he die?  

As a favor to Alex who brought her back from the blackness, Jess agrees to appeal her case and investigate what truly happened to him.