The Newton Letter by John Banville

A man is so caught up in imagining dramas and dark secrets among his landlord's family that he fails to notice the real-life tragedy that is going on. John Banville's narrator in The Newton Letter will be a familiar figure to anyone who has read his other books - even those under his crime-writing alias Benjamin Black. He is damaged character, cut adrift from the world who drinks too much, is aloof and misses what has been going on right under his nose.
A sub-plot is the life of Sir Isaac Newton, who the narrator is writing a biography about. However, like Newton's work as a scientist the narrator's biography has stalled. The narrator reflects upon a letter that Newton wrote in which he mentions an "ailment" which has afflicted him.
"He mentions... the absolutes of space and time and motion on which the picture of the mechanistic universe in the Principia is founded, and trots out again, but without quite the old conviction, the defence of such absolutes exist in God, which is all that is asked of them. But then suddenly he is talking about the excursions he makes nowadays along the banks of the Cam, and of his encounters, not with the great men of the college, but with tradesmen, the sellers and the makers of things". (P59)
Similarly, Banville's unnamed narrator moves from Dublin to spend time in Co Wexford where he plans to finish his book on Newton but finds himself unable to continue and caught up in trivialities. He rents a house from what he believes to be an old Anglo-Protestant family. They come to obsess him and he finds himself constructing biography of their lives based on his observations.
Edward and Charlotte, live with their niece Ottilie and a child David, who the narrator at first assumes is the son of Edward and Charoltte but later realises is actually Ottilie's son. He begins an affair with Ottilie but eventually comes to the conclusion that he is in love with Charlotte. As he gets to know the family better he has to deconstruct his initial speculation about them - they are not Protestant but Catholics - and develope new ones, only to find that these are wildly inaccurate as well.
Banville sums up the entire plot of the novella towards the end when he writes: "I spent a summer in the country, I slept with one woman and thought I was in love with another; I dreamed up a horrid drama, and failed to see the commonplace tragedy that was playing out in real life. You'll ask, where is the connection between all that, and the abandoning of a book? I don't know, or at least I can't say, in so many words. I was like a man living underground who, coming up for air, is dazzled by the light and cannot find his way back into his bolt-hole. I trudge back and forth over the familiar ground, muttering. I am lost." P95
This is bite-sized Banville and pretty much sums up what he is about, although I only had to look up one word – 'succubus' – compared to his later novels in which he keeps droping in willfuly obscure words that had me constantly reaching for a dictionary.