the connection of this with what Mr. Cupples had told him of the Mandersons' married life must have formed itself in the unconscious depths of his mind. Certainly it had presented itself as an already established thing when he began, after satisfying himself of the identity of the murderer, to cast about for the motive of the crime. Motive, motive! How desperately he had sought for another, turning his back upon that grim thought, that Marlowe–obsessed by passion like himself, and privy perhaps to maddening truths about the wife's unhappiness–had taken a leaf, the guiltiest, from the book of Bothwell. But in all his investigations at the time, in all his broodings on the matter afterwards, he had been able to discover nothing that could prompt Marlowe to such a deed–nothing but that temptation, the whole strength of which he could not know, but which if it had existed must have pressed urgently upon a bold spirit in which scruple had been somehow paralysed. If he could trust his senses at all, the young man was neither insane nor by nature evil. But that could not clear him. Murder for a woman's sake, he thought, was not a rare
