A man nearly succeeds in income tax fraud but is given away by a chance remark associating Christmas and Halloween.

This is another Black Widower story where the trick is exceedingly slight. (In this case, it has to do with the fact that 10 would be written in octal as 12, and 31 octal is the same as 25 decimal. So if you assume that “10-31” is a set of two numbers the former in decimal and the latter in octal, and switch the base for the two, you get “12-25” and go from Halloween to Christmas.) It’s a really obscure point, not at all obvious, and more than a little bizarre. The result is a badly strained story which one could easily do without.

Found In

	Casebook of the Black Widowers