The dead body of a beautiful girl in a disused house, the secret meeting room in the cellar, a baffling murder mystery... âThe Dagger and Cordâ is another mystery by Aidan de Brune (Herbert Charles CULL). Itâs all great fun and the author keeps the action moving along swiftly, as he always did. Wonderful entertainment and highly entertaining. If you havenât discovered the joys of Bruneâs mysteries there is a good place to start. Aidan De Brune was a Canadian-born writer who settled in Australia. In the 1920s and 1930s a number of his novels appeared in Australian newspapers as serials, and he also appears to have written serials specifically for publication in newspapers.