The universe and most of the characters in this story were created by Eiichiro ODA. This story is a tribute to his work and is not made for profit.
"While the offer is tempting" said the stranger. "My path leads away from yours."
"Where are you headed?" Luffy asked.
"I have some things in East Blue I need to take care of right away," he answered. "I will try to catch up to you after that. You should try to leave here quickly a vicious storm will be passing this area in about three hours but if you leave now and follow your log post you will avoid it."
"How can sense that a storm is coming at that time?" said Nami who sensed nothing of the sort."
"I am very good at predicting the weather." he answered.
"What about you old man," Luffy asked. "you do not have a boat?"
"Do not worry about me." The stranger replied. "Unlike you Luffy I am a very good swimmer. Goodbye to you all oh and Robin I hope you find the Rio Poneglyph. I found it a most interesting read myself." With that Robin gasped and the stranger jumped into the water and took off at an alarming speed.
"He knows what is on the Rio Poneglyph," said Robin. "We have to follow him."
"Look at how fast he is going" said Usopp "I do not think that we would be able to catch him."
"We will find what is on the Rio Poneglyph on our own," said Luffy. "Nami steer us in the direction of the log pose"
"Yes captain," Nami replied.