Panicked refugees are pouring into the port city of Phlan, fleeing from barbarian attacks in the Moonsea North. Something ominous and ancient drives the horse nomads to attack their neighbors. Poised to shatter the ancient monument keeping him from Faerûn, a "lost god" from Toril's past sends an agent from the Elemental Chaos to herald his long-prophesied return… "Monument of the Ancients" is an adventure for 13th-level characters.

If myth and legend are to be believed, the antediluvian monument defends a region of Faerûn where the boundary between the world of Toril and the Elemental Chaos is weakest. At the monument's heart lies the Anchor of Chaos, an arcane bulwark sealing a cosmic fissure between the planes. Were the enchantment powering the Anchor to fail, the Moonsea North would stand defenseless against a full-scale invasion by forces of elemental evil. Unbeknownst to the citizens of Phlan, that day is nearly upon them.