The House of Hades

Frank notices the monsters eat green roots and is relieved they are vegetarian. He holds hands with Hazel and wonders if he can turn into a rhino to protect her. Nico leads them through the streets to the edge of a plaza with the god’s house and a dozen cow monsters. Halfway across the plaza, Hazel stumbles on a cobblestone, and green roots sprout up underneath her. The monsters stare, and Frank realizes their gaze is poisonous before the creatures attack.

Nico and Hazel bolt while Frank tries to turn into a rhinoceros, but Mars’s and Ares’s voices distract him, so he stays human. Frank turns into a lion and starts killing monsters. They back off except for one, who charges and blasts him in the face with poisonous gas. Frank forces himself not to breathe and feels dizzy. Frank turns human and sees Hazel slumped against the wall. Nico says she got a blast of gas to the face. The monsters bellow for reinforcements, and Nico tells Frank to turn into an eagle and fly Hazel back to the ship. A man appears at the door of a black house and says he can cure her.

Safe inside, Frank sets Hazel on the bed concerned about her green appearance. The man says they were attacked by katobleps. Frank asks if the man can cure Hazel, so the man examines her.

Frank wonders if Hazel is doing a death trance like Nico, and the man freaks out when he learns Nico and Hazel are Underworld children. He turns Nico into a corn plant and reveals he’s Triptolemus, the god of farming. He threatens to turn Frank into a plant, so Frank pulls out the book from Akmon and Passalos. Triptolemus is thrilled, so Frank asks him to heal Nico and Hazel.

Triptolemus has a feud with Hades because Demeter gave him his powers. A child of Hades also killed one of his wheel pythons, so his chariot can’t go anywhere. Frank offers to fix his chariot in exchange for letting Nico and Hazel go and giving them aid in defeating Gaea. Triptolemus agrees to Frank’s terms, but if Frank fails, his friends die.

Frank doesn’t see any katobleps in the streets. Mars and Ares argue in his head, and Frank asks the war god about serpents. Ares and Mars say Frank must prove his worth and cleanse Venice like Horatio for them to turn an enemy into a snake. Frank gets a vision of Horatius the Roman general single-handedly holding off a horde of invaders on a bridge to save Rome.

Frank unearths roots and ties them to his belt. The katobleps gather, and Frank runs through the city transforming into different animals and taunting the monsters until all of them follow. He leads them to a bridge empty of people where the monsters charge and Frank sees red surrounded by the blessing of Mars. He kills all the monsters except one, which he asks Mars to turn into a snake. The katobleps charges, Frank kills him, and it turns into a python. Mars appears and tells Frank he did well, but Frank’s greatest test will come when he faces Gaea’s armies at the House of Hades. Frank looks and feels different, which is a blessing from Mars.

Frank takes the python to Triptolemus and demands healing for Hazel and Nico. Triptolemus dithers until Frank slams him into the wall and threatens him. Triptolemus heals Hazel with herbs and transforms Nico. He tells them to take barley to soak up the poison in the House of Hades then flies away.

Percy and Annabeth follow Bob through Tartarus, which Annabeth is convinced is the actual body of the god Tartarus. Bob explains he jumped into Tartarus because Percy needed him. Annabeth thinks about how Percy, Thalia, and Nico fought him as Iapetus, wiped his memory, and then dropped him at Hades’s palace where he became a janitor. She feels sorry for him and is scared he is going to remember his old identity, but they can’t survive without him, so she keeps following. Bob leads them to a Hermes shrine that fell into Tartarus long ago; monsters avoid it. Bob says giants are chasing them, but they can rest for a little bit. Annabeth is nervous about leaving Bob on guard, so Percy decides to keep watch also. Annabeth sleeps.

Annabeth has nightmares about her journey to Camp Half-Blood that change into Athena speaking through Reyna, the praetor of Camp Jupiter. She tells Annabeth the Athena Parthenos must be delivered to Camp Half-Blood by a Roman. Athena tells her to hurry and send the message, then she disappears as Gaea rises. Annabeth wakes up screaming. Percy brings her food that was sacrificed to Hermes from the mortal world. They eat and realize it’s from Camp Half-Blood. Bob says they should leave because the monsters will be here soon. Annabeth is angry Percy told Bob about their journey, but Percy says they need him. Bob says they can’t go because they need to get the death mist to hide them from monsters. Before they leave, Annabeth picks up a napkin and uses Riptide to write a message to Rachel, the Oracle of Delphi. Bob burns the message on the altar, and they leave.

Tartarus is so dark the only light is from Riptide and a glowing Bob. Annabeth trips and falls on the Titan Hyperion being reformed. Annabeth wants to kill Hyperion before he wakes up but sees Bob studying him. They are identical twins except Bob is silver and Hyperion is gold. Percy reminds Bob that some monsters are good, and some are bad. Bob is a good Titan, but Hyperion is a bad Titan because he tried to kill lots of people. Bob is still unconvinced because Hyperion looks like him, but Percy says he’s not good like Bob. Bob kills Hyperion with his broom saying he’s a bad Titan and can’t hurt Bob’s friends. Annabeth is concerned about Percy; either he trusts the Titan too much or he is calculating, and Annabeth doesn’t like either option.

After walking a long time, Bob senses something, and they surround it. Bob gets ready to spear it, but Annabeth stops him when she sees a calico kitten. It rubs against Bob, who picks it up. It climbs on the Titan’s shoulder and sleeps. It flashes to show its skeleton, and Percy realizes that the Titan Atlas raised it from a skeleton tooth in the Titan War. Bob calls him Small Bob and announces he’s a good monster. They keep walking and enter a forest where flying monsters called the arai, which means curses, surround them.