A 'Slide In' is an impromptu lecture in which the speakers are presented with a slide show for which they have not prepared. They must extemporise authoritatively on the contents of each slide they see. In this documentary, celebrated architects Isi Metzstein and Andy MacMillan discuss the buildings and plans shown to them over the course of 45 minutes. The architecture covers designs from medieval times to the present day. They are armed with nothing but their mutual good natured teasing and a bottle of whisky. Isi Metzstein and Andy MacMillan worked together as chief designers with the Glasgow architectural practice: Gillespie, Kidd & Coia. The practice was founded in the 1927 by Messers Gillespie and Kidd with Metzstein and MacMillan joining in the 1950s. Their own work their received a retrospective over several floors at the Lighthouse design museum in Glasgow in 2007. Both 'Lessons in Architecture' and 'Slide In' were commissioned for this retrospective.