But Hanslet stared at the knife in silence, his brain a whirl of conflicting theories. If the Professor was correct in his assumption, Copperdock was a victim of the unknown assassin. How did this knife, which, as Whyland said, was exactly similar to those with which Tovey and Pargent had been killed, come into his possession? On the other hand, if Copperdock had been the murderer, what became of the Professor’s theory? Why should one of the jurymen wish to murder his colleagues? The problem became more complicated with every fresh discovery.

“This blessed case would drive an archangel to drink,” he observed disgustedly, as he wrapped up the knife again and put it in his pocket. “Well, we’d better go across and see what young Copperdock has to say about this, eh, Whyland?”