Yesterday

You sidle up to the man you take to be the tour leader. He is probably about fifty, is wearing a loud Hawaiian shirt, and is speaking with authority about the evening ahead. You tell him that you couldn't help overhearing about the evening ahead, and you wondered whether there would be room for an extra body.

The man considers your request, and gives you a broad smile. "Sure, we are down on numbers today. If you can pay for transport and a meal, then feel free. It should cost about fifty euros, but it should be a good evening. Lots of alcohol and dancing."

Its quite a lot of money, but it sounds like fun.