On a dark and stormy night... here's a chance to spring a sudden and horrifying Mythos event on your Investigators as they're scurrying through the rain on a rural road just outside of Arkham. Suitable for a one off game or as a side-adventure to throw into your regular campaign, it involves the party quite literally running into a chain of unnatural nightmarish events that threaten both their sanity and their very lives.

As said events are under the direct control of the Keeper, you can make this potentially deadly or merely very, very scary as you prefer.

The backstory is suitably dark yet coherent, fitting well with the locale and the individuals involved. Getting the investigators involved requires no more than them happening to be driving on a wet and stormy evening... hence the suitability of this adventure for just dropping in to an ongoing campaign. It is a location-based adventure and fairly free-form - what happens after the initial encounter will depend on how the investigators react. Support for the Keeper is excellent, however, with plenty of resources to enable you to handle just about anything that the investigators might decide to do. There is also some good advice about how to run the adventure, driving the action forward and maintaining suspense while allowing time for investigation. Much of it is good general advice for how to introduce and manage the appearance and effect of any horror, and well worth reading by any GM wishing to improve on this aspect of their game.

All the NPCs are presented in full with loads of background to help you portray them appropriately. Whilst designed for the latest edition of Call of Cthulhu (7e), there are notes to help you if you'd rather use an earlier edition.

Hmm. It's not raining (yet) but I think I'll go round up some players...