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There was a novel I read back in the day about a boy who travels back and forth between a mirror-image of our universe.

I am afraid I cannot recall much about the plot, except that mirrored food is inedible and when mirrored ketchup packets were brought back from the other universe they taste like chocolate and mess you up.

Could someone help me identify this book?

After going through organic chemistry back in college, I think it should be required reading for any writer who has a story where the characters land on alien planets and find everything to be edible.

marked as duplicate by Otis, Jason Baker, Blackwood, Adamant, Ward - Reinstate Monica Oct 6 '16 at 5:15

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This sounds like The Boy Who Reversed Himself by William Sleator. The characters were able to move around in higher-level dimensions (four-dimensional space, five-dimensional, etc.) They didn't visit a mirror universe, exactly — what happened was that, if they weren't careful, they could get themselves turned around and come back to our world as their own mirror image (kind of like how you can take a piece of two-dimensional paper and flip it over by moving it through three-dimensional space). I definitely recall the bit about food tasting different when you were reversed.

  • That's right, I remember something about them interacting with creatures in higher dimensions now. This is good, thanks! – S. Albano Sep 3 '12 at 4:20

This plot device was also used in Roger Zelazny's Doorways in the Sand, although I don't recall ketchup being involved. The protagonist spends some time mirror-reversed, and can't digest most food because of this. Bourbon, however, is said to have its taste improved by the effect. He also has to hold paperwork up to a mirror to read it.

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