From publisher blurb:
"The noxious haze hanging over the battlefield smells of blood, metal, and waste. Black, oily smoke rises in thick clouds from giant fire pits fueled by alchemical concoctions and the bodies of the dead. Somewhere in the distance, an eruption of purple eldritch light fills the sky. The clash of steel, the screams of rage, and the wails of the dying are everywhere. The din is almost unbearable.
This war has caused such loss that none any longer care whether enemy or ally is being dumped onto the massive funeral pyres. The mounds of corpses have become a hazard for both sides. Swarms of rats make the ground seem alive and the sky is darkened with ravens. The flesh of the fallen writhes as beetles and maggots feast on the remains. "
The purpose of these books is to help DMs put together an interesting encounter in a short time. Each Adventure Keys release does this by starting with a unique location that can be inserted seamlessly into an existing world with little or no modification. They are modular, with many options and variants available so that the DM can customize it to suit their needs.
There are six sections that include the Location, Hooks & Goals, Characters, Trappings, Threats, and Changes. All but the first have multiple options each, and since the DM isn’t limited to using only one option, the variations available are quite numerous. Sections can be used or ignored at the DM’s discretion, or even modified based on the situation or to scale its Challenge Rating.
The options are deliberately non-specific for ease of use. The DM can include them as they are, combine them, or use them for inspiration to create an entirely new options.