The Red Thumb Mark

This theory of yours, Jervis, does great credit to your ingenuity. We may disregard the improbability, seeing that the alternative theories are almost equally improbable, and the fact that emerges, and that gratifies me more than I can tell you, is that you are gifted with enough scientific imagination to construct a possible train of events. Indeed, the improbability–combined, of course, with possibility –really adds to the achievement, for the dullest mind can perceive the obvious–as, for instance, the importance of a finger-print.