Rowan Hisayo Buchanan has achieved that rare feat, in her second novel Starling Days, of writing a convincing novel about depression which manages, miraculously, not to be in itself depressing. Her success is partly due to the fact that her protagonist, Mina, is not flattened by her despair and remains alive enough to become fascinated by another woman, Phoebe, her husband’s best friend’s sister. When Phoebe asks her to say something about herself, Mina considers what she might voice:

I want to run my tongue along the dent in your collarbone that your top has made visible. Nope. Sometimes I want to die and sometimes I want to buy a box of tomatoes and stand by the fridge eating them out of a paper carton and I don’t understand how I can hold both desires. Nope.

But Mina is brave enough to pursue this relationship, perceiving that it may transform her life.

Her husband, Oscar, is sympathetically drawn, and the intense claustrophobia of caring for someone with a mental illness carefully evoked, not least when he buys her roses to cheer her up and she sighs. ‘Oscar wanted to sigh too. But you didn’t get to sigh when you were the healthy one.’

The novel’s other great triumph is to leave trails of clues as to Mina’s mental health so that the reader has to play detective. This not only feels real — mental illness is not easily contained and defined — but also creates a narrative propulsion that powers the plot.

Mina is first seen hovering at night on George Washington Bridge and is stopped by the police. The reader knows almost as little as the police at this point: does she really have to go to work the following day? And does she have a husband who will collect her? Unravelling the truth is one of the considerable pleasures of this beautifully written novel.

Very occasionally, Buchanan’s observational inventiveness gets the better of her: she describes a hipster café carefully but then marginally overdoes it by comparing the size of two men’s beards to small dogs. But this really is nitpicking over writing which is startlingly original without — on the whole — drawing attention to its originality. Starling Days also offers scenes of sex between two women which don’t titillate, worryingly but importantly pointing up how rare this is.