The Play's The Thing - Novigrad
This quest automatically begins following the completion of the Count Reuven's Treasure Story Quest. First you'll need to return to Priscilla and speak with her to advance this quest forward (pictured above). For this quest you'll need to make a play in order to lure Dudu out of hiding.
Geralt will be asked for a little bit of input for making the play, all that matters in the dialogue is that at the end you choose Comedy for the nature of the play. If you choose Drama then a riot will break out during the play, complicating things.
Best Result For Play: Comedy, Name doesn't matter
After Priscilla is done writing up the play she will send you off to give the script to Madame Irina. Follow the white dots on your compass to find her, you'll have to buy a ticket for 50 Crowns to get into the area Irina is. Speak with her and she'll update your quest again, giving you two new objectives. You need to recruit ushers from the docks and some jugglers from the Puffins group, the latter being optional.
If you wish to recruit the Puffins (it increases how much EXP and Crowns you earn) go into your quest log and select that objective as your main one, head over to their residence and you'll find them being bullied by some thugs. Fighting the thugs is inevitable so don't bother trying to pay them off, just tell them to Go Away then fight them.
On the docks Sofus will help advertise the play for you if you beat him and a friend in a fist fight. You also have to give him some Crowns before the fight but you'll get them all back if you win. With everyone hired return to Irina and discuss who is going to play which parts in the play. Here's who you should choose:
As for you, you'll be playing the Witcher. If you want to give a perfect performance you'll want to memorize your lines - or cheat and use my guide! Here are the lines you will want to say for the best possible outcome/performance:
"To slay beasts most foul..."
"Perhaps 'midst the guests..."
"Seems men's hearts..."
"But a base heart...."
"No monster is he..."