“Want to see something cool? The ice cubes here have nine corners.”

I didn’t believe her at first, but after reluctantly removing one from my glass, I found that she was right. From any given angle, it looked like a normal ice cube, but as I rotated it between my fingers, I could feel an invisible vertex passing along my thumb. “Weird. How do they do that?”

“It’s a pretty neat trick. First, they freeze the water into old-fashioned, six-sided cubes. Then, a fancy android rotates each cube through four-dimensional space until a seventh face is exposed.” She made a twisting gesture with her hand. “Because only six faces are frozen at this point, the seventh is hollow, allowing more water to be poured into the gap. The robot fills it to the brim, then puts it back into the freezer until all seven sides are solid. As a result, the cube holds twice as much ice within the same volume, but it also ends up with an extra corner.”

I dropped the cube back into my scotch and took another drink. It sank to the bottom of the glass, proving that it was indeed more dense than the surrounding fluid. “That seems like an awful lot of work for nothing. Why go through all that just to make ice cubes?”

“Isn’t it obvious? This way, they take twice as long to melt.”

Pretty neat trick, huh? Want to see another one?

If a bartender has access to twice-frozen ice cubes, they probably know how to make ambrosia.

The Illuminati are known to use this method of hiding ice within ice to smuggle their signature contraband.