A little friendly competition can be fun now and then - unless, of course, the competition isn't friendly at all. Included in I13 Adventure Pack I - https://www.adventurelookup.com/adventures/i13-adventure-pack-i TSR 9202

The adventure begins with the characters discovering the recently murdered Returned, Varyas, and confronting his killers. Varyas's gold mask bears a code on it, one that points toward the sage Khea who lives in the nearby polis. When the characters investigate, they learn from Khea that the writing is undecipherable except for the first line, which refers to the legendary Court of Orestes, a site sacred to the god Phenax. She also notes that a recent earthquake has uncovered a cave along the Khystonos River that could be the secret site's location. If so, then perhaps within lies the key to deciphering the mask, along with its own treasures. With the information provided by Khea, the adventurers set forth into the wilds, where they'll face multiple storied dangers before reaching the Court of Orestes. Once at the lost holy site, the characters discover ancient guardians, as well as an unliving entity with the potential to reveal Phenax's lost secret.