The Spider's Thread (蜘蛛の糸, Kumo no Ito) is a 1918 short story by Ryūnosuke Akutagawa, first published in the children's magazine Akai Tori.
Kandata was a cold-hearted criminal, but had one good deed to his name: while walking through the forest one day, he decided not to kill a spider he was about to crush with his foot.
Moved by this single act of compassion, the Buddha takes the silvery thread of a spider in Paradise and lowers it down into Hell.
Kandata, looking up by chance at the sky above the pool, sees the spider's thread descending towards him and grabs hold with all the might of a seasoned criminal.
He read Fyodor Dostoevsky's The Brothers Karamazov in English translation sometime between 1917 and 1918, and the story of "The Spider's Thread" is a retelling of a very short fable from the novel known as the Fable of the Onion, where an evil woman who had done no good at all in her life is sent to hell, but her guardian angel points out to God that she had in fact done one good deed in her life: she once gave an onion to a beggar.