Portrait of an Unknown Lady by María Gainza; The Trouble With Happiness by Tove Ditlevsen; The Land of Short Sentences by Stine Pilgaard; The Old Woman With the Knife by Gu Byeong-Mo

Portrait of an Unknown Lady by María Gainza, translated by Thomas Bunstead (Harvill Secker, £14.99)
Insincerity, said Oscar Wilde, “is merely a method by which we can multiply our personalities”. It’s a principle that María Gainza applies with brio to her dazzling novel about art and authenticity, seeing and not seeing, evocatively titled La Luz Negra (The Black Light) in its original Spanish. There are plenty of unknown ladies in the book. Our narrator is unpicking the life of her late employer Enriqueta, “the single, despotic authority on the price and authenticity of all paintings”, who turns out to have been providing fake authentication for forgeries, particularly of works by the real-life artist Mariette Lydis. An assemblage of literary quotations, court papers, auction catalogues and the “fairground kaleidoscope” of memory, the novel packs a huge amount into its 208 pages. If the reader is never quite sure what’s fact and what’s fiction, that’s just part of the fun.