The author provides an extensive argument to prove that the origins of the Vedic tradition lie in the Harappan civilization. He utilizes both archaeological and linguistic evidence, as one would expect. It seems like a convincing argument although I'm not an expert on the subject. Less appealing is his vindictive tone, although that's also partly understandable given some of the nonsense that western authorities have professed about ancient India in the name of 'objective' science.