I need a few lines of nasty Perl 5 code.

I am writing a talk for beginning Perl 5 programmers covering how to read a line of code and I need a few nasty lines that are fairly self contained. These should be normal lines of code (no obfuscation), they just need to have a lot going on in them. Things involving multiple maps with complex bodies would be good. If you have one or more such beasts, would you leave a comment with them?

The talk will be given at The Pittsburgh Perl Workshop.