When readers met Eliza Tok in Shade and Sorceress, the first instalment of Catherine Egan’s Last Days of Tian Di series, she was a 12-year-old just getting used to the magical world she had been thrust into. In Bone, Fog, Ash and Star, the third and final entry in the series, Eliza is 16, and facing the challenge of saving the boy she loves.

It has been more than a year since Eliza left the Citadel, where the Mancers (a powerful race of magical beings) informed her that their world, Tian Di, has been split into two: Tian Xia (for the powerful, including witches, fairies, and other magical creatures) and Di Shang (for humans). Eliza has also learned she is the Shang Sorceress, responsible for ensuring that beings from Tian Xia do not enter the human world. Free of the Mancers’ oversight, Eliza resolves to retain control over her power. She is equally determined to spend time with Charlie, a “Shade” who can change into various animals and beings. Eliza is on the verge of confesing her true feelings for Charlie when a group of Thanatosi assassins attempt to kill him.

Each book in this trilogy features a journey, and Eliza’s final quest leads her through mountains and forests, often on the back of a dragon. The descriptions of these flights are awe-inspiring. Egan excels at character development: Eliza’s best friend, Nell, a bookworm who jokes about how difficult it is to study while riding a dragon, has grown from an immature preteen in the first book into a brave and mature adolescent. Another standout is Swarn, a witch who was once a threat but has a newfound fondness for Eliza.

The book is full of action, to the point that at times there is almost too much going on. However, much of the exposition detailing the ancient history of magic, which weighed down previous instalments, is absent here. Moments of humour – most notably between Nell and Charlie – also help keep readers interested when the story starts to veer off in different directions.

With its mix of comedy and tragedy, magic and charm, Bone, Fog, Ash and Star is a satisfying, moving conclusion to an enchanting series.