Haunting: Whitehead & Mies is about an architectural design research project based on a study of Mies van der Rohe's self-proclaimed interest in the thought of the British mathematician and philosopher, Alfred North Whitehead. The research question asks: what was 'this thing' Mies believed he had begun to share with Whitehead in 1926? The answer is sought where Mies said he set it down, i.e., in his buildings and it is given in the discursive essay and architectural proposition set out in this book. Haunting: Whitehead & Mies is a re-working of an earlier publication of the same title, published in 2015 by the Big Air World. It is a supplement to /Atmosphere/: The Origin of AIR Grid, which was published in 2018 and was in turn based on the authors original doctoral thesis of 2004.