From the back of the book:
Face the Serpentine Siege
The Keep on the Borderlands is assaulted by Benwick and his scaly forces, as you rally your own allies and prepare yourself for battle. Can you turn the tide and defeat Benwick and his alliance of evil before Restwall Keep is laid to waste?
Keep on the Borderlands: A Season of Serpents (Chapter 5) is designed for five characters of 3nd level and is the fall and winter 2010-11 season of the D&D Encounters official play program. This Dungeons & Dragons adventure includes a full-color battle map, ready-to-play encounters, and DM information on the D&D Encounters official play program.