Acoustic Return

A cast-bronze speaking tube mouthpiece sat jutting from the tiled bulkhead, its acoustic flap seized with green verdigris. I halted. Tool canister placed firmly on a dry marble balustrade. I stepped close, the dark water lapping evenly against my heavy greaves. My armored thumb pressed the counterweight lever with steady, deliberate force. Brine crust fractured with a dry pop. The weighted bronze flap swung open, resting against its stop. I leaned forward, resting the rim of my dive helmet against the funnel. Distant ocean churn breathed through the pipe, rhythmic and unobstructed. Subterranean conduit open. Channel clear.