This is the sixth 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 half-mortal 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, Demon is on his way back after saving the phoenix, as related in book 5 of the series. On his long journey back he meets Eunice, the nereid (whom he met in the book Steeds of the Gods), who tells him that her sister Thetis has fallen in love with a prince from Aegina. Demon tells her that his friend Peleus is from Aegina yet he is too young to be thinking of marriage. 

When Demon arrives at Chiron's cave, he finds a small crowd of girls. His Pegasus, Keith, warns him that these are Maenads and that he should escape. Apparently, Dionysus, whom the Maenads follow, came to Chiron seeking relief for an upset stomach. Demon is startled and is rescued from the rough group by Chiron at the last moment. Chiron helps them and they leave. 

Demons discovers that Chiron has brought with him Asclepius' baby daughter, Hygeia. The baby is in bad condition since she refuses to eat anything and Chrion wishes to try to heal her.

Demon must return to his stables after the long journey. There he hears Endeis (who took care of the stables in his absence) gossiping with the nymph Althea about Zeus. Apparently, his eagle is upset since Zeus spends his time as a pigeon on earth to attract a princess.

Later Demon returns to Chiron's cave when suddenly big Pegasus arrives. (In the story, Demon treats smaller Ethiopian Pegasi in the stables, one of his favourites is Keith. Big Pegasus is The flying hose form the Greek myth). Big Pegasus is badly burnt and injured since he fought the chimera with Bellerophon. Pegasus pities the chimera which had only tried to defend itself. Demon treats him and as a gift of gratitude, Pegasus gives him several of his hairs which are knotted as a bracelet. He promises Demon that if he is ever in danger and needs him he should call him three times and if he can, then he will arrive to his rescue. Then Bellerophon arrives, and haughtily takes Pegasus away, which he is able to do because he has his magic bridle. Demon is angry with the hero but cannot do anything. Meanwhile, Demon must tend to the chimera as well, since it was badly wounded during the fight. 

Suddenly Demon receives a message from his father, telling him that he must go and visit his mother since there is a problem with man-eating mares in her village. This is the first time Demon visits his mother since he arrived in Olympus, and he discovers that he has two new siblings: Agatha and Ajax.

The mares were dropped in the village by Heracles since Eurystheus did not want them and jumped into a jar to avoid them. Demon must take the mares to the stables and cure their appetite for human flesh. Hermes helps him by bringing Morpheus, who plants a dream in the mares’ minds and make them dream of peace and hay. In return, Morpheus asks for Demon's dreams, which he uses to mend the holes in his cloak (we are not told which dreams Demon gave him). The trick succeeds and the mares tell Demon how they were maltreated by Diomedes and Heracles.

Later, Demon encounters the new goddess Psyche. She weeps since she must get Zeus' eagle to help her retrieve waters from the Spring of Eternal Youth for Aphrodite so that the goddess will allow Psyche and Eros to marry. Demon hesitates but then he agrees to help her. Meanwhile Chiron asks him to bring the nurse goat Amaltheia, since Hygeia is starving and fading, but Amaltheia is too old to breastfeed her. Amaltheia and her companion. Golden Dog, help Demon visit Zeus' eagle, who agrees to help him and Psyche. The group then arrives at the spring and fetch the water but then they are attacked by a three-headed giant snake. Zeus' eagle must return to his master and Demon and Psyche are rescued by Pegasus.

When Demon returns he gives the water to the goat and she becomes younger and her milk saves Hygeia. Psyche then marries Eros. Demon is summoned to Zeus, because he borrowed his eagle without permission, but Amalthea and the eagle defend his actions and he is pardoned. Demon is then promoted to Stablemaster of Olympus; he will also receive an assistant to help him with his work.

Aside from the adventures, this volume focuses on the theme of mothers and families. Demon's mother has almost been forgotten in the narrative and now she has a new family. She tells Demon she felt lonely after he left. Perhaps the author wished to show that she recovered and found new joy in her life, although her new children cannot replace her elder son. During his trip to earth, Iris chastises Demon for neglecting his mother as he did. "'It's not my fault', he thought, furious. 'The gods have kept me so busy I haven't had a chance to visit home'. But a tiny, guilty part of his brain wondered if he should have tried harder." [location 315]. The mother character remains undeveloped in this narrative and almost unimportant. Now that she has the twins, it is almost if the readers (and Demon) do not need to worry about her since she moved on with her life. A similar neglected parent is Amaltheia the nurse goat. She openly blames Zeus for failing to visit her and care for her after she raised him.

The negative portrayal of heroes continues with Bellerophon, who is so self-absorbed that he does not even care about Pegasus' condition and only uses him as a tool to achieve his own goals of heroism. Demon names him "big beast-hurting bully!" [location 233] but with no effect.

Psyche is described as whiny and pitiful. Here she is a new goddess, but she does not have all of her powers yet, since she has not finished her task for Aphrodite. She threatens Demon, saying that he must not tell anyone that he saw her crying, and is very vain, "'If you EVER tell anyone you saw me looking like this, boy,' she hissed, 'I will tell Aphrodite you put beast poo in her nightie drawer.'" [location 471]. She then orders him to bring her Zeus' eagle. Even this new goddess threatens to turn him into a beetle and squash him.

In the end, Demon surpasses his master Chiron and receives his approval since he helped cure Amaltheia using the spring's water. "'Well done, my young apprentice. Well done! You've succeeded where your master has failed.'" [location 814]. This is an important step in Demon's growth and this stage comes after he spent time with his father in the previous volume and fulfilled his duties toward his mother in this volume. In this story, the message is to take care of the ones you love, whether parents or pets; this is the truest reward.

McLain, Lee, "What Makes a Good Fractured Fairy Tale?", The Horn Book Inc, May 21, 2015 (accessed: August 3, 2021). 

The review refers to the Kindle edition (9781848125971).

The illustrator of this Kindle edition is David Roberts and the publisher is Piccadilly Press, London.

See under "Addenda" Beasts of Olympus (Series, Book 1): Beasts Keeper.