What a magical mystery tour of a novel. A lot of the time I found myself as bemused as poor Dr Watson as what exactly was going on and who all these mad characters were, between maharajahs, femmes fatales, midget monocle manufacturers, doppelgangers, an aesthete who makes soup brewed from a mammoth’s femur… the list goes on and on.

Oh, and a couple of real people have walk-on parts, including Frederick William Burton, Irish-born artist and director of the National Gallery (dubbed William Frederick in the book – a mistake or part of the overall hall of mirrors effect?). Irish people will know him as the painter of the ineffable ‘Meeting on the Turret Stairs’, held in the National Gallery of Ireland and in 2012 voted Ireland’s favourite painting [see below]. Even Queen Victoria turns up in the book and is revealed as a good chum of our…