Mobile technologies in the ancient Sahara and beyond: edited by C.N. Duckworth, A. Cuénod and D.J. Mattingly. Cambridge, Cambridge University Press, 2020, 511 pp., £90/$120 (hardback), ISBN 978-1-108-83054-6. Also available as an eBook ($96), ISBN 978-1-108-90395-0. Issue 4 (2nd October 2021)