Professor Challenger and his Lost Neolithic World combines the two great passions of the author's life: reconstructing the Neolithic mind and constructively challenging consensus in his professional domain. The book is semi-autobiographical, charting the author's investigation of Alexander Thom's theories, in particular regarding the alignment of prehistoric monuments in the landscape, across a number of key Neolithic sites from Kintraw to Stonehenge and finally Orkney. It maps his own perspective of the changing reception to Thom's ideas by the archaeological profession from initial curiosity and acceptance to increasing scepticism. The text presents historical summaries of the various strands of evidence from key Neolithic sites across the UK and Ireland with the compelling evidence from the Ness of Brodgar added as an appendix in final justification of his approach to the subject.