It is Thursday afternoon, the 13th of August. Time for your history lesson. But your history teacher Professor Jura hasn’t shown up yet. She has always been strange. But today is even stranger. She has left a message on the blackboard:

“Past, present and future are in danger!"

Dr. Quarks will attack soon! I need your help! I have sent my time machine back to your present to pick you up. Activate it and find me in the past. You will find the machine and instructions in my secret lab. Quarks is looking for it too. He will attack the lab at exactly 3pm in your present, if we don’t stop him earlier in the future. But first things first: here are all the clues you need and my key. Please hurry! Prof. Jura

Just when you have finished reading the last sentence, the caretaker walks in and hands you a box with your names on it. “Jura asked me to give this to you”, he says. Then he turns, silently cleans the blackboard and leaves the classroom without any further comment. Weird! “Are we really going to activate a time machine to meet Prof. Jura in the past so we can fight a certain Dr. Quarks in the future before he can destroy something in the present?! Is this even real?!”, one of you asks. “Maybe it’s just part of her adventurous museum project.”

While you open the box, the school bell rings for the 2pm break: exactly one hour until the supposed attack. “Well, we will never find out if we don’t find the lab. Does anybody know where Prof. Jura lives…?”