A - possibly 'the' - classic campaign for the Call of Cthulhu RPG.
It is... merely okay.The campaign material ticks all the right boxes for a Cthulhu campaign - secret societies, sorcerers, ancient uncaring entities, etc. - but these are stitched together in a rather pedestrian fashion. SoYS is a campaign of its time, and feels rather old-fashioned in it's railroading and tone.
I feel it is also a tad on the too expensive for a really old PDF of average quality. One for collectors or game historians only I think.
[3 of 5 Stars!]