Afterparty

Taken from TA's Walkthrough:
Go right to The Schoolyard Strangler, and you'll see Polly downstairs in a now empty bar. Follow Polly as you converse. She will express her disappointment in finding Roberto (rightfully) innocent, but will still honor the drinking contest as you were trying to do the right thing.
You now need to complete the drinking contest. It doesn’t actually matter if you win or lose, as you’ll get your seal irrespectively. If you accidentally messed up the drinking contest when you were helping Fela earlier in the story, this is another opportunity to complete a perfect drinking game (although more difficult as Polly is a quicker opponent). Either way, once the contest is completed Polly will grant you with your seal (you can also find out how you ended up in Hell, if you so wish)