the one channel in the family that worked
both he and Jim had got a chance to become comfortable in mutual silence
Context
The exception proves the rule: the father could be easy only with Mario, and only because Mario couldn't speak until he was six, so the two of them built their bond inside silence instead of talk, on a shared love of lenses that carried none of the freight of needing to please or be approved. Where every spoken channel in the house jammed, the wordless one held — presence and a common object, not conversation, turning out to be the family's single reliable way of being together. [sweep · shared-ground film-optics fathers-sons]