One day Hades got really mad at his brothers because he couldn't live in the regular world with them.
So he shot fire and lave up from the underworld into deserted mountains.
Turning the very dry gray mountains into erupting volconoes.
Poseidon and Zeus were startled by what happened so they entered the underworld which was guarded by a three headed dog named Curberus.
Then Poseidon asked Hades why he was doing this.And he said it was because he was jealous so they asked him what he wanted.Hades said he wants to see the real world and so Hades Zeus and Poseidon Rode Cerberus to the real world.
So the three bothers went up to Mt. Olympus and cleaned up all the ashes from the volcano then they all went back to their rightful realms.