Dangers in the Abyss

From publisher blurb:

In a race against time to prevent a powerful gateway from being unsealed, a descent into the abyss beneath Black Dog Pit turns into a frantic battle against hordes of winged terrors. When our intrepid explorers reach the ancient cavern floor, they still have to face a vastly superior force, in the Dangers in the Abyss! Each Sidetrek Adventure Weekly episode throws characters into an action-packed encounter designed to electrify your game. Drop any Sidetrek Adventure Weekly directly into your adventure as a stand-alone combat. Or, if you dare, link all 12 into one pulse-racing, white-knuckle sidetrek adventure series. Jump aboard Sidetrek Adventure Weekly tonight!