Beast in the Shadows by Edogawa Rampo / 100-page paperback published in 2023 in the Penguin Modern Classics Crime & Espionage Series
A mystery writer turns detective to protect the woman he loves. But is he hunter or hunted?
The chance meeting between a crime novelist and a married woman blossoms into friendship. When she confides to him that she has been receiving threatening and sadistic letters from an ex-lover, who says he is watching her in the shadows, he knows he must help her. But the trail unexpectedly leads to another writer, Oe Shundei, the mysterious and secretive author of works of grotesque violence. Suddenly nothing is as it seems, and nobody is safe.
Edogawa Rampo was the pseudonym of Taro Hirai (1894-1965), generally viewed as the greatest of all Japanese suspense and mystery authors. He was a prolific novelist and short story writer. Much influenced by writers such as Conan Doyle, Chesterton and Wells, his pseudonym is a Japanese transliteration of Edgar Allen Poe's name. Many of his works have been made into films. Perhaps his most famous stories outside Japan are 'The Caterpillar' and 'The Human Chair'.