Ekrem Imamoğlu of the CHP opposition party has been arrested days before his likely nomination as a presidential candidate. We speak to the deputy chair of the party and gauge international reaction to what is being described as an attack on democracy. Also on the programme, the effect 'The Knowledge' test taken by London cab drivers has on the brain, and a dispatch from Bergamo in northern Italy, five years after military trucks brought home the reality of the unfolding Covid pandemic.