White to play. Trent-Carlstedt, Hamburg 2022. Lawrence Trent spotted a way to deliver a quick mate. Which move did he play? Answers should be emailed to chess@spectator.co.uk by Monday 20 June. There is a prize of £20 for the first correct answer out of a hat. Please include a postal address and allow six weeks for prize delivery.

Last week’s solution : 1 Rc1! with the idea 1…Kb8 2 Kxb6 Ka8 3 Rc8# After 1…b5 or 1…Ka8 White plays 2 Kc7! and 3 Ra1#

Last week’s winner Vivien Fowler, Saffron Walden, Essex