This is the eighth and final book in the Beasts of Olympus series. Pandemonius (or Demon as he is most commonly referred to in the series) is the 11 years old son of the god Pan and the mortal Carys. Demon is the official beast keeper of the Olympic gods and it is his responsibility to take care of the various beasts. In this story, Demons returns from Asgard and then enters a deep sleep, during which he prays for Morpheus to help the mad wolf Fenrir to find peace. Morpheus agrees but warns Demon to be careful in using the dream catcher next time.

Demon later follows Hephaistos, the Pleiades and the Colchian dragon to a volcano, since it appears that the giant Typhon is waking. Demon manages (with the help of the dragon’s gas) to calm the giant’s many animal heads and Typhon is calmed once more. When Demons returns to the stables, he is urgently summoned by Artemis, who has sent her dogs to fetch him, due to a serious illness which has spread among her herd of unicorns.

While it has become customary for the Olympians to ask for Demon’s help while threating to harm him if he fails, this time, finally here is an objection to Artemis’ threats. While she threatens to feed him to her dogs, they refuse, protesting that they like him. She then threatens to encase him n the forest’s pine trees, but Pan objects this as well. In the end, Artemis takes Demon to the unicorns but, however, disguised as a girl since they do not allow any boys near them.  

Demon examines the herd and discovers that they were poisoned by underworld pomegranate seeds. Artemis helps Demon save them by making them bask in moonlight. Demon then adds sky star ingredient (something that he used against Typhon earlier in the book). The stardust was given to Demon by Electra, the invisible Pleiada who took a liking to him and followed him around after the Typhon mission. The herd soon recovers and Artemis goes down to the underworld to punish Hades and Persephone. As it turns out, the pomegranate seeds were blown to earth by mistake, following a fight between the married couple when Persephone pulled up the pomegranate trees in the underworld and flung them at Hades, who threw a darkness bolt at them, causing the seeds to come up to earth where, influenced by Persephone touch, they immediately grew. In the end, everyone rejoices in celebrating the unicorns’ recovery.

This story concludes the series. Demon is a healer now, who can work on his own without needing help from his mentor Chiron. He uses his skills and his brain to come up with a diagnosis as well as a cure for the suffering animals. Furthermore, Demon receives the ultimate love from the animals and more importantly, the recognition he wished for from his father, which symbolizes his maturation.  While Artemis threatens to harm Demon, Pan appears to chastise her: “Our pine trees will not take him, Moon Lady, nor will any of the trees of our sisters,” said the tallest. “Do not threaten the son of Pan.” “No,” said a deep, velvety voice, like mossy bark on ancient trees. “Do not threaten Pandemonius in my forests, Artemis. I will not allow it.” A tall figure with thick, hairy goat legs stepped out from between the trees. Demon let out a gusty sigh of relief. His dad had arrived! “He’s a good boy and a good healer,” Pan said. “It’s time you Olympians showed him some respect. Most of you threaten him and treat him like dirt, but who do you turn to when one of your precious beasts is sick? Has he ever let any of you down?” Demon’s heart swelled, and he felt tears prick at the back of his eyes. His dad had neglected him for most of his life. In fact, he’d never even met the forest god till he came and whisked Demon away to the Stables of the Gods. But it seemed his dad had been noticing things after all. And now he was standing up for him against Zeus’s own daughter.” (p. 34).  Here we see the closure which Demon needed. His absent father shows his admiration and love for his son and is even willing to risk himself by standing against an angry goddess.

Pan also criticizes the Olympians for always bullying his son, although he never failed them. Thus the gods are revealed as petty and disrespectful to Demon. From Pan’s point of view, Demon deserves the gods’ respect and gratitude for his actions.  This time, Artemis follows Demon’s order regarding the unicorns’ treatment. She takes down the moon so they can be healed by its light. She shows true love and care for her animals which makes her less cruel in Demon’s eyes. Demon judges one’s character according to the way they treat animals, hence he finds kindness even in the less sympathetic gods, for example, Hera. 

Demon also continues trying to help the Norse wolf, Fenrir, now that he is home again once more reflecting that the power of the Greek gods, in this case, Morpheus, appears to surpass that of their Norse counterparts.

This story also adds a gender-transforming element. Demon becomes Pandemonia in order to safely approach the unicorns. This part alludes to the goddess who traveled accompanied by female companions. By this disguise, Demon becomes more sensitive to what it is like being a girl, even for a little while. His understanding and sympathy is not as deep since he does not relate to women’s feelings or character, only to external signs, yet it is a start in the direction of acceptance and tolerance: “He supposed, all things considered, a dress and long hair weren’t really that bad. And the garland did smell awfully nice.” [p. 60] Demon is not a transgender character, however, he does show that if one decides to change from one gender to another than it should be OK and we should find the best in each gender.

In this story, Demon is again aided by female characters: Electra and Artemis. Furthermore, it is a woman’s wrath, Persephone, which brought about the problem in the first place. 

Regarding the mythological references, there is a brief inclusion of Typhon and the Pleiades, as well as a nod at the rocky relationship between Hades and Persephone, who do not seem to be happily marriage. In the previous book, Demeter joined Demon on his journey to Asgard and we are told that she was upset since Persephone was in the underworld. In this story we understand that Persephone is not too happy being there as well, due to her fight with Hades. Although the couple’s fight is used as the background for the illness which attacks the unicorns, the author does use this opportunity to subtly hint at the problems within Persephone and Hades’ marriage and how their unhappiness can affect others, even harm them.

The review refers to the Ebook edition (9780515159530)