I have vague memories of a sci-fi story that involves "the whisper line" as a crucial plot device. The whisper line refers to 2 secret points in a highly oppressive prison institution between which it is possible for 2 inmates to hold a private conversation without anyone else's notice.
Sadly, all other plot details escape me.
I seem to remember these other features:
- Darkness, silence, and the routine of life in the institution
- The institution was submerged (subterranean?), possibly in a ravine, reserved for Jon Smith type dissidents
- Long quiet struggle and shifting fate for a mostly limp and powerless protagonist
- An unlikely bond between characters who grow to sympathise with each other in an almost animal sense (prior enemies drawn together in prison, I deduce)
- Slow, unsensationalist observation of the dehumanising effects of authoritarianism
The vivid feeling I have of the last 2 makes me think this could be an Ursula Le Guin novella, but I'm fairly sure I've read all her material in the last 5 years or so and haven't been able to retrieve this.