Sword Art Online Alternative Gun Gale Online, Vol. 5 (light novel)

As the third Squad Jam begins to wind down, the "special rule" takes effect! "Your former comrades are now your enemies." Team LPFM, one of the favorites to win the competition, has been torn apart, and Pitohui couldn't be more delighted! Not looking forward to her rematch with the trigger-happy Pito, Llenn and her new teammates are escorted to the mysterious UNKNOWN area at the center of the sinking map, surrounded by a thick fog. As bullets of betrayal fly past former allies, the fog finally clears to reveal...a luxury cruise ship?!