Chapter 5 of Final Fantasy VII Rebirth, titled "Blood in the Water," involves the party fighting monsters that have infested the Shinra-8 cruise ship. The attack is caused by Shinra's experiments on Jenova cells, leading to passengers and crew being mutated into various creatures, including the Jenova Emergent, which the party must defeat to survive. The chapter involves fighting through multiple parts of the ship, rescuing Barret, and culminates in a boss battle against the Jenova Emergent.