White to play and mate in two. Composed by Sam Loyd, Sunny South, 1885. Nearly all Black’s legal moves can be met by Qg8 mate, but White must prepare a response against 1…Rg7. What is the key first move? Answers should be emailed to chess@spectator.co.ukby Monday 19 July. There is a prize of £20 for the first correct answer out of a hat. Please include a postal address.

Last week’s solution 1…Re2 threatens perpetual check with Re1-e2. After 2 Qxg4 Rg2+! it was draw agreed in view of 3 Kxg2 Rf2+! and stalemate soon follows.

Last week’s winner Luke Brown, Newcastle