R. Austin Freeman, The Red Thumb Mark — Chapter XI (1924)
“ And now, what is the nature of this projectile?""I should say it is a miniature shell or explosive bullet.""Wrong!" said Thorndyke. "A very natural inference, but a wrong one.""Then what is the thing?" I demanded, my curiosity still further aroused."I will show you," he replied. "It is something much more subtle than an explosive bullet—which would really be a rather crude appliance—admirably thought out and thoroughly well executed. We have to deal with a most ingenious and capable man." ”
