The Last Letter ♦ By Fritz Leiber

On Tenthmonth 1, 2457 A.D., at exactly 9 a.m. Planetary Federation Time— but with a permissible error of a millionth of a second either way— in the fifth sublevel of New- New York Robot Postal Station 68, Black Sorter gulped down ten thousand pieces of first-class mail. This breakfast tidbit did not agree with the mail-sorting machine. It was as if a robust dog had been fed a large chunk of good red meat with a strychnine pill in it. Black Sorter's innards went whirr-klunk, a blue electric glow enveloped him, and he began to shake as if he might break loose from the concrete.

He desperately spat back over his shoulder a single envelope, gave a great huff and blew out toward the sorting tubes a medium-size snowstorm consisting of the other nine thousand, nine hundred and ninety-nine pieces of first-class mail chewed to confetti. Then, still convulsed, he snapped up a fresh ten thousand and proceeded to chomp and grind on them. Black Sorter was rugged.