What can I do at Gio's tavern?

Not have a drink, as you might have guessed.

It's okay to look at the bottles, though.

Look at the shelves of bottles to find out that one shelf is only a FACADE.

Look at the bottle and cards picture above the shelves.

It's as if it's trying to tell you something.

Does the configuration remind you of anything?

Or the number on the cards?

There are three bottles. In the upper two bottles, the 4 is (are?) in. It's out of the lower bottle, though.

Three bottles, and a four for each bottle. Ring a bell?

What else is there three of in this very tavern?

Remember those tables and chairs?

Move all chairs of the N tables in, and all the chairs of the S table out.

Turn around. Where did that click come from?

Try the facade again. It now swings open to reveal a safe.