From the publisher's website:
Beneath the Heart of Empire is an OSRIC(tm) module designed for 6-10 adventures of levels 3-5.
The capital of the Venirian Empire has been re-located back to Venir, and a thriving city has been built above the swallowed ruins of the old city. Various connections to the old city can be found in the sewers, cellars, and other underground portions of the rebuilt city of Venir, and adventurers frequently plumb these depths in search of the secrets and treasures of the empire’s glory days. What lurks beneath the Heart of Empire?
Note: The cover states that the adventure is for 6-10 adventurers of levels 3-5, but the introduction states that it is for 6-10 adventurers of levels 1-3; judging by the creatures used, the inside information is correct and the cover is incorrect.