D&D 5E: Fantasy #16: Cave of the Unknown

A level 3 adventure for 5E. A forgotten cavern beneath a lonely hill hides secrets as old as the multiverse. Strange phenomenon haunt those who delve into its depths. Both the wise and the mad venture within to call upon the cave’s ancient power—and not all emerge from the darkness. Now, the legend of the Cave of the Unknown reaches the ears of stalwart adventurers. Can then unravel the Cave’s secret history and succeed where others have failed? Or will their bones soon litter the darkness under that distant hill?