For a tier 3 module, this is an underwelming adventure. The fire snakes felt like they were just a placeholder beast that could have been replaced by literally anything and you wouldn't notice. The choice to use a warlock for the last encounter instead of a wizard or cleric build felt uninsired.
At this tier, you need to challenge players. This adventure was dull. Not bad enough to hate, but lacked anything to make it memberable.
[3 of 5 Stars!]