Once this tangle of adventures is put to bed and the presence of a Skaven master-plan uncovered (or, at least, hinted at rather strongly), the second half of the campaign is much more traditional, with a roughly linear plot that culminates in a big old battle in the mountains.

It's easy to find several different strands of the adventure playing out simultaneously, and while this is gratifyingly open-ended it can be tricky to keep track of all the dangling threads unless your party is particularly single-minded. This entire section can easily be thought of as a series of interlinked, shorter adventures rather than a single monolith of plot, with Skaven schemes and imperial investigations unfolding as the days pass. The first of these is a tense and treacherous investigation into what the hell's going on in Middenheim, where the party needs to not only uncover the Skaven's dastardly schemes, but accumulate evidence proving that the rat-things actually exist - apparently a matter of some debate in the Empire. The campaign is broken up into two roughly even halves.

From rat-ninjas through to an undead spy-rat (complete with a gramaphone-esque hearing trumpet jammed in its back), they help to make every moment a marvellous mixture of hilarious and horrifying - exactly what you want from Warhammer's Old World. They don't turn up too much in the earlier parts of the book, but every time they do it's a delight. These nasty blighters are a race of hideously mutated rats, and when run properly they can alternate between slapstick stupidity and creeping horror over the course of a single sentence. There are a handful of reasons you might do this, but chief among them has to be this volume's designated bad guys - the Skaven. However, though the book itself is at pains to point out that it works best when used as part four of five, you could get a lot of mileage from running it solo - albeit, with some of the long term plot threads trimmed out and the party's starting XP cranked up. As the fourth and penultimate part of the sprawling Enemy Within mega-campaign, The Horned Rat is designed to slot into an ongoing game set in and around the city of Middenheim, and a decent chunk of its content is devoted to keeping the threads of chaos corruption and general unrest that have been neatly cultivated in previous volumes.

Download the horned rat warhammer