HISTORIA ARCANUM 5E: HERALD OF RAIN5th Editions Historical Universe returns. A 250 page Adventure Module, Historica Arcanum: Herald of Rain takes place in the 13th century Silk Road. Within this adventure, the party will clash against the legendary Grand Master of the Assassin Order, Sabbah. Emboldened by the Silk Road's impending downfall at the hand of the Khanate, Grand Master of the Assassin Order, emerges from the shadows! Unlikely heroes, thrown into fray as loose ends, must