By the Lake is a character study of a married couple, the Ruttledges, and their neighbors who live around the same lake in Ireland. The reader is dropped straight into the middle of things without any introductions. "The middle of things" is an overstatement, because nothing in the present happens much, beyond calvings and the occasional visitor. Mostly the characters tell stories about each other and gradually you get to know everyone in the village, and hear about all their tragedies and small victories, which sounds like a recipe for sentimentality. But this book isn't saccharine.
I loved the dialogue, for example in this passage in which Ruttledge has counted the money his rich uncle ("The Shah") is keeping with him for a few days:
"You could buy a house and land with this. You could get married. You could start a life. You could go to Africa or America," Ruttledge said as he prepared to put the box away. "It's there like strength."
"It's better than the other fella having it, anyhow," the Shah agreed uncertainly; and Ruttledge decided not to protest or joke any further.
McGahern died in 2006 and the New York Times obituary described his work this way:
Because he was an Irish writer, Mr. McGahern was inevitably compared to James Joyce. Because his stories were set in the country, he was compared to Chekhov and Hardy. His style was terse. His novels moved deliberately through their agonies of love and misgiving, always with reference to the dominating Catholic culture and the rigors of wresting existence from the fields and the peat bogs.