Conrad’s novella takes place one night on a boat by the Thames, a mesmerising tale of one man’s search for another. Published in 1899, it sprang from his experience in the Congo nine years before. What became Heart of Darkness begins then, with Conrad noting the rapacious, violent nature of ivory-trading and colonialism. In July 1890 he spent day after day looking at decomposing bodies, skeletons tied to posts, men shot: he wrote, when a 13-year-old boy came in with a gun wound to his head, that he would be “glad to see the end of this stupid tramp”. The “tramp” went on, and Conrad watched men die, dreams end and, as his Congo journey came to its close, he noted in a letter: “I have lived long enough to realise that life is full of griefs and sorrows which no one can escape.” Afterwards, he was spent: there was a cost – weakened physical health and an exhausted mental state that would bubble up into breakdown 20 years later but which, a decade after, strangely became a defining work of our literature.