Discussing his own work, Lett-Haines, who had been well-known to many members of the European avant-garde during the 1920s, retrospectively listed the movements and artists that had had most impact on him, 'Influences apart from classical were Wyndham Lewis in London 1918, Giorgio de Chirico in Italy 1922, W Kandinsky in Germany 1922 and Pablo Picasso in France always kept me in good heart' (unpublished article, Tate Archive). Of these artists, The Dark Horse seems most indebted to the metaphysical landscapes of de Chirico (1888-1978), and Percy Wydham Lewis's (1882-1957) work of the late 1920s and early 1930s.
During his period of residence in Paris from 1921 to1927, Lett-Haines often visited Tunisia and Morocco; indeed, a knowledge of Islamic architecture is evident in the Moorish setting of The Dark Horse. His impressions of North Africa are captured in the numerous postcards (Tate archive) he sent to his partner, Cedric Morris (1889-1982), and in his articles (Tate archive) on various aspects of local cultural practices. Both sources suggest that he found there a refreshing alternative to the European culture he was accustomed to.
In The Dark Horse Lett-Haines has created a dream-like composition in which various scenes and perspectives blend into one another. The hidden and the revealed, the dark and the light are repeatedly juxtaposed. The silhouetted figure in the lower left corner walking through a dark interior is adjacent to a similarly sized figure shown outside in full light; the pale crowd in the square is contrasted by the dark figures running down the alleys. Elsewhere the partially obscured horse in the square balances the dark horse in the centre of the picture. Dividing the two is a row of arches that acts like a threshold between them. There are numerous other examples in the composition of similar threshold devices marking out the interior from the exterior, of which perhaps the most remarkable example is the hidden chamber revealed beneath the floor on the right-hand side. What is happening in the chamber is not clear, but a naked woman appears to be clinging to, or tied to, a pillar. Around her are other naked figures. It is not known whether the various scenes reflect events in Lett-Haines's life, but collectively they do seem to form a journey into a mysterious subconscious existence.
It is not possible to identify a particular town from the architecture in the picture, but certain features do seem to correlate with specific places. The faintly outlined building in the upper centre, to the right of the tower and beneath the fronds of the large palm tree, is, for example, highly reminiscent of a mosque in Tunis, of which Lett-Haines kept several postcards in his archive. As there is no record of Lett-Haines visiting Africa in 1934, it is likely that Dark Horse was painted from memory at Pound Farm near Higham, Suffolk, where he and Cedric Morris had lived since 1929.