Demigods & Magicians is a collection of three short Crossover stories between The Camp Half-Blood Series and The Kane Chronicles by Rick Riordan. The short stories are called "The Son of Sobek", "The Staff of Serapis" and "The Crown of Ptolemy". These stories take place the summer after the end of The Kane Chronicles and The Heroes of Olympus series. During his The Sword of Summer book tour in 2015, Rick Riordan declared the completion of the short stories as their own book.
"The Son of Sobek" (2013) is the story in which Percy Jackson meets Carter Kane. The story starts with Carter revealing that he was eaten by a giant crocodile he was looking for, and an introduction. Thankfully; however, he is saved by Percy, but the monster escapes. Through a misunderstanding, the two get in a fight, which ends in a truce once they are reminded about the monster crocodile. While running towards the monsters the two introduce themselves to each other, and Carter reveals that the crocodile is a petsuchos a son of Sobek. Finding the monster in a cul-de-sac, the two fight against it and defeat it. At a diner afterwards, Percy and Carter give the rundown to each other, and Carter draws a hieroglyph on Percy's hand in case they need to contact each other again.
"The Staff of Serapis" (2014) is the story in which Annabeth Chase meets Sadie Kane. It starts with Annabeth trying to catch the F train to Percy's place after having a rough day, or at least until she spots a weird looking monster, which looks like a lion and wolf stuck together and wedged into a hermit crab shell. Much to Annabeth's surprise, though, the monster doesn't attack her and boards the A train, leaving her to pursue it. While following it, she figures out that the monster is made up of 3 pieces and is missing a part of itself, before she encounters Sadie fighting the third piece of the monster at the first Brooklyn stop, which looks like a black labrador retriever with the back end of a tadpole. Unfortunately, the monster Annabeth was following escapes, but the two manage to capture the monster Sadie was fighting and introduce themselves and discuss what is happening. Eventually the two come to the conclusion that the monsters are in fact the remains of a staff trying to fix itself, but unfortunately the part of the staff that they captured escapes. The two are then forced to follow it towards a magical storm creating a lighthouse. Once inside they meet the risen god Serapis, who claims to be trying to recreate the old empire he was supreme god in and to drain the power of the other gods. Unable to allow him to succeed, Annabeth and Sadie put a stop to him and his goals.
"The Crown of Ptolemy" (2015) starts off with Percy and Annabeth trying to summon Carter and by extension his sister Sadie; with the hieroglyph he was given in "The Son of Sobek", to help them fight Setne. Unfortunately, the Kane siblings don't answer forcing the two demigods to attack Setne themselves. However, their attack doesn't work, with Setne quickly defeating them with his magic and then summoning the goddess Wadjet. After summoning Wadjet, Setne took a selfie with her (much to the goddess' irritation) just before taking her crown and consuming her essence. Setne, now done with the goddess, turns towards Percy and Annabeth to consume them too in order to grow in power, but thankfully fails. He does, however, consume Percy's sword Riptide and began to try and suck everything in. Thankfully, the Kane siblings finally show up, forcing Setne to retreat. The four realize that Setne is trying to make the crown of Ptolemy and will soon try to take the goddess Nekhbet's crown; the hedjet, to complete the crown of Ptolemy and consume her essence as well. Together the four agree that the best way to fight Setne is to use his own strategy against him and mix their powers together. It works, and Setne is finally defeated. Afterwards, the four agree to keep in contact in case anyone else tries to combine Greek and Egyptian magic.
- All Myths Are True: Classical Mythology and Egyptian Mythology, thanks to the two series this work is a crossover with.
- Attack of the 50-Foot Whatever: The petsuchos is a giant crocodile.
- Call-Back: Setne was on the loose at the end of The Serpent's Shadow, third book of The Kane Chronicles. These short stories are about him being found and dealt with.
- Circling Vultures: Sort of a Defied Trope. Vultures do circle Setne, but that's only because he's summoning the goddess of vultures, Nekhbet. That said, Setne does end up defeated for good.
- Deity of Human Origin: Setne's ultimate goal, and he nearly succeeds.
- Everything's Better with Penguins: Though they don't appear in the book, it's mentioned that the labrador monster fought Felix's penguins.
- Feathered Serpent: The flying snakes Setne is seen with in "The Crown of Ptolemy" are subtly implied to be uraei.
- Much like vultures appear while Nekhbet is being summoned, the flying snakes appear when Wadjet is being summoned; uraei and cobras are sacred to her.
- A God Am I: In "The Crown of Ptolemy", Setne keeps on referring to himself a god and to his credit he nearly did become one, with the keyword being "nearly".
- Hybrid Power: A major plot point for this series. Hybridized Greek and Egyptian magic can draw power from and freely travel through both mythological worlds. This means Greco-Egyptian god Serapis and Greco-Egyptian Magician Setne can No-Sell magic from any single mythos, and absorb power from them to the point they can bring both pantheons to heel and potentially Take Over the World. They can only be countered by similarly hybridized magic, like Egyptian Magician Carter using Annabeth's invisibility cap or Greek demigod Percy being a Willing Channeler to Egyptian god Nekhbet.
- Jerk Ass Gods: Serapis, Nekhbet and possibly Wadjet, though her limited characterization makes it hard to tell. That said it should be noted that the quote below was made before Wadjet even knew what Setne had in store for her.Wadjet: You dare take a selfie with the cobra goddess?
- Magic Staff: Sadie uses one, plus there's also Serapis' staff.
- Making a Splash: The petsuchos and, naturally, Percy display this.
- Mistaken for Racist: In "The Son of Sobek", Percy, not knowing of the existence of Eygyptian magicians, assumes Carter is a demigod, so he asks him if he's a "half-blood". As Carter happens to be biracial, he's offended, not knowing what Percy meant, leading to a fight.
- Morph Weapon: When Percy and Annabeth are given the Kanes' wands to use Egyptian magic, they turn into their Weapon of Choice Celestial bronze and all, only instead of being Greek weapons they were their Ptolemaic equivalent.
- Mix-and-Match Critters: Serapis' staff is not only alive, but has the upper body of a lion, wolf and dog.
- Never Smile at a Crocodile: The petsuchos is a giant monstrous crocodile. When the necklace that makes it a petsuchos is removed it becomes a regular baby crocodile and is moved into the Brooklyn House.
- Our Monsters Are Weird: The monster(s) that make up Serapis' staff.
- Pun: Setne seems to like these. The best one is probably after her gets stabbed by Percy."About that... I'm beyond dying now. At this point" He tapped the blade. "Get it? This point?"
- Secret Keeper: At the end of "The Crown of Ptolemy", Percy, Annabeth and the Kanes agree not to tell anyone else on their respective sides about the existence of the other pantheon and monsters. They also agree to keep a look out for anyone else trying to use hybrid magic so they can stop them.
- Short Story: This book contains three; "The Son of Sobek", "The Staff of Serapis" and "The Crown of Ptolemy".
- Spell Book: The Book of Thoth.
- Swirly Energy Thingy: Setne apparently does this to try and kill Percy and Annabeth in "The Crown of Ptolemy".