The Mark of Janus

On the third finger of a black-haired, brutish fist
Is wrapped a two-faced ring
That leaves the mark of Janus
On the hapless faces of the helpless victims
Of the hawk-nosed, green-eyed thug
But then a careless moment came
The ringed fist met wet cement
And got stuck there
At a loss for words he was
Unable to utter even
You dirty rats