Death in Venice by Thomas Mann, 1912
Death in Venice is a novella and the plot is quite simple: aging composer Gustav von Aschenbach - a man in his fifties, who seems much older - has lost his artistic inspiration. Unable to write, over the course of several agonizing days he wanders the streets at all hours, winding up in unsavory districts where an unnamed menace lies - menace in the form of a sneering, redheaded man who never approaches him but nevertheless represents, or reflects, danger and despair.
Eventually, Aschenbach decides a change of scenery may help revive him, rekindling his lost artistic fervor, so he packs is bags and winds up in beautiful Venice. Only, when he arrives, and is ferried to the Lido by gondola (the Lido being a common landing point for tourists seeking lodging in the city) the gondolier is yet another redheaded, sneering man who all but kidnaps von Aschenback, refusing to let him out when the older man expresses trepidation about the gondolier's attitude.
When they arrive at the Lido, however, the gondolier disappears. The authorities were there waiting for him, to arrest him for being the only gondolier in Venice without a license. Von Aschenbach has thus been taxied for free. It's a foreshadowing of things to come, of the despair yet to be, once again accompanied by a redheaded man.
After a few restless days in which he still can't manage to settle, von Aschenbach is on the verge of leaving when he sees a beautiful young man: a man whose spirit and handsomeness begins to consume him. He becomes obsessed; he cannot look away from the man. Though they never meet, the young man is very aware of the attention he's drawing. No doubt he feels flattered While they're in Venice a cholera epidemic sweeps through, killing and sickening many.
