From Kirkus Reviews:

"The never solved mystery of the raid on Bermuda obtain gun powder for Washington's liberation of Boston in the Revolutionary War is the kernel of fact for this adventure. A rather contrived narrative takes young Tom Rawlins to his older brother's military encampment outside Boston, gets him involved with the high command, including Washington himself. Aware of certain Loyalist sympathies in Bermuda and of Tom's ability as a boy, to take messages without arousing suspicion, the General sends him to Captain Barnaby, alias ""Mr. Harris"". Tom sails with him on his ship for the islands and after the usual amount of stumbling blocks, they drug the governor while a big party is going on and make off with the gun powder."