"The Swimming-Pool Library" by Alan Hollinghurst

Young, gay, William Beckwith spends his time, and his trust fund, idly cruising London for erotic encounters. When he saves the life of an elderly man in a public convenience an unlikely job opportunity presents itself - the man, Lord Nantwich, is seeking a biographer. Will agrees to take a look at Nantwich’s diaries.

But in the story he unravels, a tragedy of twentieth-century gay repression, lurk bitter truths about Will’s own privileged existence.