Excellent scholarly work on the origins of the Sitra Achra. Far from the usual fair of Kenneth Grant and the mass amount of LHP material that is prolific everywhere, Mercer looks back at different transliterations of the texts of the Zohar and the Torah to highlight the references and origin of the Sitra Achra, separating the Sitra Achra from the 'Qlipoth' in the process. The writing is professional and is without hints of any type of agenda or buzzwords.