It appears to me that this mystery is considered insoluble, for the very reason which should cause it to be regarded as easy of solution - I mean for the outré character of its features.

If we could fly out of that window hand in hand, hover over this great city, gently remove the roofs, and peep in at the queer things which are going on, the strange coincidences, the plannings, the cross-purposes, the wonderful chains of events, working through generations, and leading to the most outré results, it would make all fiction with its conventionalities and foreseen conclusions most stale and unprofitable.

It is a case, Watson, which may prove to have something in it, or may prove to have nothing, but which, at least, presents those unusual and outré features which are as dear to you as they are to me.