you--as being a man of sense and an accomplished mathematician--a
fit apostle for the Gospel of the Three Dimensions, which I am allowed
to preach once only in a thousand years: but now I know not how to
convince you. Stay, I have it. Deeds, and not words, shall proclaim
the truth. Listen, my friend.

I have told you I can see from my position in Space the inside of all
things that you consider closed. For example, I see in yonder cupboard
near which you are standing, several of what you call boxes (but like
everything else in Flatland, they have no tops or bottom) full of
money; I see also two tablets of accounts. I am about to descend into
that cupboard and to bring you one of those tablets. I saw you lock
the cupboard half an hour ago, and I know you have the key in your
possession. But I descend from Space; the doors, you see, remain
unmoved. Now I am in the cupboard and am taking the tablet. Now I
have it. Now I ascend with it.

I rushed to the closet and dashed the door open. One of the tablets
was gone. With a mocking laugh, the Stranger appeared in the other
corner of the room, and at the same time the tablet appeared upon the
floor. I took it up. There could be no doubt--it was the missing
tablet.

I groaned with horror, doubting whether I was not out of my sense; but
the Stranger continued: "Surely you must now see that my explanation,
and no other, suits the phenomena. What you call Solid things are
really superficial; what you call Space is really nothing but a great
Plane. I am in Space, and look down upon the insides of the things of
which you only see the outsides. You could leave the Plane yourself,
if you could but summon up the necessary volition. A slight upward or
downward motion would enable you to see all that I can see.

"The higher I mount, and the further I go from your Plane, the more I
can see, though of course I see it on a smaller scale. For example, I
am ascending; now I can see your neighbour the Hexagon and his family
in their several apartments; now I see the inside of the Theatre, ten
doors off, from which the audience is only just departing; and on the
other side a Circle in his study, sitting at his books. Now I shall
come back to you. And, as a crowning proof, what do you say to my
giving you a touch, just the least touch, in your stomach? It will not
seriously injure you, and the slight pain you may suffer cannot be
compared with the mental benefit you wi