White to play. So–Vachier-Lagrave, Paris, June 2021. The queen on e7 can be taken, but Black’s last move was …Rd8, counterattacking White’s queen. Which move did White play to expose the flaw in this idea? Answers should be emailed to chess@spectator.co.ukby Monday 5 July. There is a prize of £20 for the first correct answer out of a hat.