Have an NPC or two trudge along.
One night, they are keeping watch for the party camp. One of them gets abducted, the other, horribly scarred, goes on a deranged rant about lizard-people.
During a party-trek along the area, they encounter all the dangers of the jungle - huge fucking liches, bugs, spiders, reptiles, poisonous plants and getting shat on by some birds.
Then, they finally get to the temple grounds, where they are met by the shrivelled, severed head of that NPC. A head, carried by lizardmen on a pole. Lots of 'em.