Nikolai Yezhov
According to Montefiore, a few days later, as Nikolai Yezhov buzzed in and out of Stalin's office, a broken Tukhachevsky confessed that Avel Yenukidze had recruited him in 1928 and that he was a German agent in cahoots with Nikolai Bukharin to seize power. Tukhachevsky's confession, which survives in the archives, is dappled with a brown spray that was later found to be blood-spattered by a body in motion.