This publication introduces a rare cache of over three hundred Tibetan-language manuscripts recently recovered from Mongolia (Ulaanbaatar) and Khams (Jyekundo, Yushu county) comprising essential works on Vajrabhairava and Yamāri/Yamāntaka by the eleventh-century Tibetan Buddhist translator and tantric master Rwa lo tsā ba Rdo rje grags, and by numerous other authors and commentators affiliated with his tradition. The centerpiece of these manuscript collections is the once mysterious compendium of Rwa lo tsā ba's personal writings known as the Rwa pod ('Rwa book'). The volume provides an itemized inventory of these manuscripts with brief descriptions and cross-references for each work. It also includes an extensive introductory study discussing the early history and transmission of the Vajrabhairava and Yamāri/Yamāntaka traditions in Tibet, with special focus on the legacy of Rwa lo tsā ba, particularly in the Sa skya lineages.