I guess it's to be expected that they will be late, but still, precious weekly gaming time trickling away!
The plot isn't quite so linear- they previously missed several key clues aboard the Jenivere, which I told them about, namely a dead cook and first mate.
The adventure is the very open ended sort- they have a whole island to roam about and gather clues, and so far they haven't encountered any NPC camps or anything more than a single dimorphodon nest.
At the next session, they'll be able to possibly Diplomacy the NPCs up to Friendly, at which point they will discover a series of quests form each of them, giving them a bit of direction along the island. Some are guaranteed to interest the players, like Ishirou's treasure map, and all of them will end up giving the players(and other NPC's ) a permanent bonus about equivalent to a trait!
I can post a map of the island if you guys want, I just avoided doing so because one of the readers was playing this adventure.