The narrative follows twin brothers who build a workshop and become skilled amateur wireless operators; when one travels to London for medical care, a chain of mysteries and maritime adventures unfolds. Their radio work draws them into confrontations with a suspicious intruder and a fog pirate broadcasting a peculiar squeak-roar signal, and culminates in a shipwreck that strands characters on an iceberg. Encounters with Arctic inhabitants, midnight raids by thieves, repeated S.O.S. calls, sea searches, and a final daring rescue showcase the boys’ practical tinkering, wireless ingenuity, and resourceful seamanship as they unravel the threats and bring events to a resolution.