Summer solstice

The Summer Solstice is the summertime meeting between the gods of Olympus.

After Percy, the son of Poseidon, survived the hellhound's attack in The Lightning Thief, Poseidon claimed him. This caused discord among the gods of Olympus, as this was proof that Poseidon had not honored the pact he had made with his two brothers.

After Zeus' lightning bolt was discovered to be missing, Zeus suspects Poseidon used Percy to steal it, and demands he return it by the Summer Solstice, and Poseidon in turn wants an apology for being suspected on that date.

A quest is given to Poseidon's son Percy to find the missing lightning bolt and return it in time in order to stop a war amonst the gods. If he failed, it would be the Trojan War all over again, except on a much larger scale. Nature would be at war with itself, and it would be many years of battle until the winner came to victory, and nothing could be sure about what the world would be like then.

Percy Jackson succeeded, and Poseidon got to meet his son formerly at the Summer Solstice. Poseidon was very sorry for Percy, because being a hero means a tragic end for most heroes. Percy told his father he wasn't sorry for being who he was, and Poseidon told him that he was a true son of the Sea god.

The threat of war was not gone, and the gods were all very relieved, and they probably had a few choice words for Ares, who had a hand in the almost explosion of battle between the Olympians.