*** Executing through print, just after undef step ***

$enemy--->undef                 Dalek:{phaser=> + } (ref=1)<-+
                                                |            |
                                +---------------+            |
                                v                            |
$phaser------------------------>Phaser:{name=> + (ref=2)     |
                                               |             |
                                +--------------+             |
                                v                            |
                                'Exterminator' (ref=2)       |
                                ^                            |
                                +--------------+             |
argument stack:  '. Bye!\n'                    |             |
                 eval('$enemy->exterminate()'  |             |
                 ref---------------------------+             |
                 '. His phaser is named '                    |
                 undef($enemy)                               |
                 obey()<-ref---------------------------------+
                 'My enemy must '