I wonder if anyone has noted the similarities between Invitation to a
Beheading and Flatland, the 1884 novel by Edwin Abbot?

Flatland is a novel about a two-dimensional geometrical figure who is
imprisoned for talking to others about a third dimension, which he has
visited, and which the other two-dimensional figures cannot believe exist.

Aspects of the two plots seem so similar to me that it's hard to believe
Nabokov had never read Flatland.

The text of Flatland can be found here:

http://www.geom.uiuc.edu/~banchoff/Flatland/

The similarities may just be an interesting coincidence - or perhaps
Nabokov read it in his youth and forgot it?

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