From the publisher's website:
"Every inn hearth is ringing with chatter and every guildhall is silently watching and preparing. Nobles are equipping adventuring parties, and religious orders are hiring sword arms to be at the ready. All of this activity centers around one fact: this is the month that the legendary Chasm of the Damned returns. The Chasm is never late; once every 37 years, in this month, a mysterious gorge riddled with caved and populated by strange creatures appears somewhere within 200 miles of the spot in which legend says it originally sat. It stays for exactly 108 hours then slowly fades away...taking with it anyone who does not escape in time. The Chasm of the Damned is designed for 4-6 characters of levels 6-10 and is compatible with 1st Edition gaming."