Discusses possible treason by way of an "intercepted Letter, directed to the Duke of Mirepoix, the Contents of which, upon a full Consideration of them, appear to me of a very extraordinary Nature, & of the utmost Importance." Mentions a Peter Ioncourt(?) as the probable author of the letter as well as a Lydius, under the employment of Shirley. "It is wonderful(?) however, to me, that W. Shirley should have engaged in such a Plan without acquainting the Government at Home with it, or with the Methods, by which He proposes carrying it into execution." Especially suspicious of Shirley's promise to protect the wives and children of the Indians in a strong place, "when there is none, I know of, in those Parts, but Fort DuQuesne..." which is the place that they are supposed to attack. Mentions that three people have already been charged with treason. In postcript writes that somebody under Shirley "was lately taken up as a spy." Noted as a copy on the upper left hand corner. Signed "Dunk Halifax." Two leaves sewn together with reddish-orange thread. Scored left-hand margin. Gilt edges and watermarked with a fleur-de-lis, V, backward C, I and VI.