The Beast of ShadowGate

Publisher's blurb: The origin of the ShadowGate is lost in antiquity. Some claim it as the work of devils, others cannibal cultists or even demon lords. Not long after its discovery it was boarded up by the priests of the local church, and then fortified by paladins. Of late something has emerged from the portal. It remains trapped within the divine defences, but for how long? A 4-hour adventure for 1st-4th level characters