SPI-M-O are at the Covid inquiry this week. They’re the shadowy group of mathematical modellers who contributed – more than most – to the evidence that backed up lockdown. On Monday we heard from Professor Mark Woolhouse of Edinburgh University. Surprisingly – for an inquiry that seems from the outset to be focused on the deaths of the vulnerable and how we should have ‘locked down sooner’ – Professor Woolhouse focused his evidence on the mistakes of lockdown.