In the novel, The Sea of Monsters by Rick Riordan  Percy, Annabeth and Tyson face many challenging obstacles. First they aboard the Princess Andromeda and found out that Luke was on there and had two friends Agrius and Oreius. They were grizzly bears. The three kids Annabeth, Percy and Tyson managed to escape the Princess Andromeda. Afterwards, they talk to Chiron in an Iris-Message. Later they go to a cabin that Annabeth, Luke and Thalia made when they were younger, Percy got hungry so he told Tyson to go find him powdered doughnuts and he gets them and Annabeth wonders where. Then they find out that Tyson got them from a shop called Monster Donuts. They find out that it is an actual shop with monsters. A monster finds them and they have to fight it, Percy cut it's head off and then found out that when you cut one head off two grow back and another Monster Donut shop is placed somewhere in the world. Clarisse ended up saving them and she took them on her ship where they had to get through the Sea of Monsters. Tyson was trying to save Annabeth and Percy so he went to go stop the fire in the boiler room and the ship blew up and he has not been seen since. Finally Percy and Annabeth go to CC's spa and resort and Percy drinks a potion that CC made and he turns into a guinea pig. Last Annabeth saves him.