Purifying a House from Blood provides an updated philological edition of the Hittite ritual for the ancient gods (CTH 446) with transliteration, transcription, and English translation. In addition to the updated critical edition, which is complemented with philological notes and commentary, this work provides a comprehensive study of this important ritual text. The introduction to the text (part 1) presents a palaeographic analysis and a brief overview of the content and the main topics of interest for a reading. Part 2 offers a detailed philological commentary. Part 3 discusses in greater detail some distinctive aspects of this composition in the broader context of the Hittite ritual corpus.