The chief designer of the Soviet space program, Sergei Korolev, was imprisoned on false charges and sentenced to slave labor. This sentence was later reduced to 'merely' eight years in a sharashka, a labor camp for scientists. That's the way to do it: first, show the victim how bad it really can be, then reduce the sentence and the severity, but only on cooperation and good behavior. "Produce or you go back to the mines to die horribly". In a totalitarian regime the stick goes a long way.

https://en.m.wikipedia.org/wiki/Sergei_Korolev