Maalathiir's Library

From the introduction: Maalathiir was an ancient sage, his library is legendary for its rare books. The library lies under the ruins of his tower. A system of tunnels dug by giant ants provides access to the library from a nearby cliff side. The tunnels lead to a large antechamber. A door in the antechamber requires a key held by a minotaur that has set up residence in the tunnels. The PCs are hired to search for a specific book in the library.