The characters are wasps from the devastated nest of Ys’drktha. The other survivors from the cataclysm are being held and tortured in the pits of the neighbouring Ak’thaan nest, being slowly dismembered and eaten by drone wasps or fed to the writhing masses of larvae.
The players see a small shrine to the local nature deity just of the trail. Before they even approach it, they can smell the foul stench of rotting meat. If they inspect the shrine, they can see it has been desecrated by rotting organs in the last few days. There is no mistaking it for an obscure ritual, the organs are thrown everywhere, not left in specific places as in sacrifice.
If the players try to clean the shrine, they will soon find it has been boobytrapped to fling sharp splinters covered in the rotting gore in every direction. While only doing a few points of damage, they injured players will likely take sick soon unless they get medical attention.