After reading mother's letter on the wharf, Louis says "language", but there's a typo in the subtitles - 'langage'.
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I suppose, it leaves room for a sequel with Louis's new adventures. Although there are several other daemons mentioned in the game. The child stolen from Venice and other Louis's siblings, including Augustus mentioned in the end. Emily and Emma, even Elizabeth, if she survives the island. The sequel can take place even in another history period due to daemons' longevity.