From the back cover:
"Captured by your master's foe!
The journey to rejoin your command, Duc Gastar d'Alcene, was uneventful, even idyllic. Your thoughts were all of the glory to be won at the Duc's service, and you hardly noticed the dismal road to Lac Lamarran. Neither the eerie countryside nor the unfriendly villages could break your sense of security -- you weren't prepared for the ambush.
Taken by surprise, robbed of any chance to fight, you were made prisoner deep in the castle, chained by the evil Duc de Binaire. Left to rot in a filthy cell, you have only your wits to help you escape the strange Castle d'Yvoire. Eluding the guard and servants will be difficult, but worse yet may be the dark forces rallied by the Duc de Binaire! You must confront them or remain a prisoner forever, just another Captrif d'Yvoire."