Mário de Sá-Carneiro was a Portuguese poet and writer. While World War I was in progress in the north of France, he quit the university and started a relationship with a prostitute. A few months later, with growing financial problems and suffering from depression, Sá-Carneiro wrote a dramatic letter to Fernando Pessoa on March 31, 1916:
«Unless a miracle, next Monday, March (or even the day before), your friend Mário de Sá-Carneiro will take a strong dose of strychnine and disappear from this world.»
Extremely unhappy with his life, he still delayed the suicide almost one month. But, as he had proclaimed, at the age of 25 he killed himself swallowing a large dose of strychnine on April 26, 1916, at Hôtel de Nice in the Montmartre district of Paris.