The pills are actually vitamins and are given by Hermes god of messengers.
he has to leave someone behind
Luke gave Percy a sand dollar necklace as a way to earn his trust and manipulate him for their own gain. Percy eventually gave the gift to Annabeth because he didn't want to keep it after realizing Luke's true intentions.
When his dad gave him a compass when he was a little boy.
Percy gave him a gold drachma and the guard let him go right in.
no
Luke gave the flying sneakers to Percy, hoping that he would get hurt. Percy gave them to Grover, having a bad feeling about them. The sneakers were uncontrollable.
In the book Ares gave Percy a backpack containing the thunderbolt but it only showed up in the Underworld.
She is around Percy's age; though the author never gave away how old she is.
It was a gift from Poseidon. Poseidon gave it to Chiron to give to Percy once he came to Camp Half Blood. Also, Zoe gave it to Percy in his dream in The Titan's Curse. Actually, the dream was scene from the past of when Zoe went against her family to help a demigod (Hercules).
mr brunner
he invented the cure for Glaucoma and other things
When he found out he had the lightning bolt in his backpack he thought back to see who could have put it there. Then, he remembered the car wash where Ares bought them burgers. When Percy and his friends were going to leave Ares handed Percy his bag after he'd put in the bolt.