“Without, however, the knowledge of pre-existing cases which serves me so well. There was a parallel instance in Aberdeen some years back, and something on very much the same lines at Munich the year after the Franco-Prussian War. It is one of these cases—but, hullo, here is Lestrade! Good-afternoon, Lestrade! You will find an extra tumbler upon the sideboard, and there are cigars in the box.”