England, 1403. Once again Ancient Pistol is called upon to perform his patriotic duty. This time his orders emanate from the highest in the land, the new King Henry IV, formerly Harry Bolingbroke, whose grasp on the throne he has usurped is so shaky that he is obliged to resort to employing the least competent secret agent in history.
Tasked with investigating unrest on the Welsh borders, Pistol is obliged to visit places he has barely heard of, such as Stafford (which he is prone to confuse with Stratford, Stamford and various other places), Shrewsbury, and the mysterious Celtic lands west of Offa’s Dyke.
One thing becomes clear: former allies of the King, such as Harry Hotspur, are no longer to be relied upon. In view of the uncertain outcome of the forthcoming battle, Pistol decides that prudence dictates that rather than commit his allegiance firmly to the new King, he should be on his own side. Meanwhile his efficiency is impaired by his usual difficulties, namely lechery, drunkenness, stupidity and cowardice.
Saucy and ludicrous escapades follow one another in swift succession before Pistol yet again emerges unscathed, or almost so, from his brushes with death, to finish on the winning side.