Chapter 542 is titled "Another Incident to Be Told".
As Ace was being escorted to Marineford by Vice-Admiral Onigumo, he was informed that Luffy is leading a riot in Impel Down. Meanwhile, at Marineford, a panicked soldier informed Fleet-Admiral Sengoku of Blackbeard's mysterious disappearance, a shocking event considering the danger of Whitebeard's imminent attack. He also told him about a mysterious marine vessel with no deployment authorization that had arrived at Impel Down.
At the great prison, Impel Down, Blackbeard and his crew arrived and quickly defeated a group of jailers, claiming that they are on the same side. The rest of the facility was warned of Blackbeard's betrayal, who proceeded into the prison.
Due to these events combined with the riots, Vice-Warden Hannyabal was beginning to panic. He suggested that he and some jailers escape, but is contacted by Magellan, who reveals that he had stopped the riot on level two by sealing the entrances and exits. Magellan told Hannyabal to stall on level four until he arrived. Meanwhile, on level six, former chief Shiryu was being let out of his cell in order to help the situation. He was warned by Magellan that there will be no second chances, and was told to go after Blackbeard. As soon as the transmission was stopped, Shiryu slaughtered several guards with his newly reunited blade, apologizing for his actions.
On level four, Luffy and his group were currently fighting their way through the guards, releasing many prisoners as they go. Chief Guard Saldeath attacked with his Blugori, but Ivankov beat them back. They proceeded, but found the path blocked by Sadi and the three Jailer Beasts. Many of their forces were defeated, but Luffy, Crocodile, and Jinbe defeated all of them with a single blow.
- new introduction