I know I told you to start here but don't forget about everything else!

You'll need to figure out the order of the numbers to make up your passcode. Have you seen what lines the location of each game is on?

How many locations are there? And how many lines? And how many puzzles?

Each puzzle piece includes one of the locations shown on the underground map. Each location is on a different coloured line, numbered 1–7. Match the location on each puzzle piece to the correct underground line to work out the order of play. The Bill of Sale is at Friedrich-Wilhelm-Platz, on the orange line, making it puzzle 1. The Invitation is at Mierendorffplatz, on the main blue line, making it puzzle 2. The Spa Ticket is at Friedrichstraße, on the purple line, making it puzzle 3. The Exhibition Poster is at Frankfurter Tor, on the brown line, making it puzzle 4. The Business Card is at Potsdamer Platz, on the red line, making it puzzle 5. The Email is at Rathaus Schöneberg, on the yellow line, making it puzzle 6. Finally, the Token is at Rüdesheimer Platz, on the pink line, making it puzzle 7. Use this order to work through the seven puzzles.

Matthias doesn’t want everything on his invoice. Can you use the Post-it note to work out which items need to be removed?

The descriptions on Matthias’s list are more literal than they first appear. Try translating each phrase into the name of an item on the invoice.

Once you’ve matched all five phrases to items on the invoice, remove those items and recalculate the total.

Use Matthias’s Post-it note to work out which items need to be removed from the invoice. Each phrase is a literal description of an item: “Chilled extremities” means Cold Feet Painting, “Dark member of the flock” means Black Sheep, “Cranium amongst condensation” means Head in the Clouds, “Incomplete round” means Broken Circle, and “Azure start to the week” means Blue Monday. Remove these five items from the invoice and calculate the new total. The remaining total is 54K, so the answer is 54.

That's an interesting theme for the party.

Everything is written in English but some of the words don't look right.

Read the street name of the address backwards. NEVES YTENINI becomes NINETY SEVEN.

Alvar would struggle to figure this one after handing in his phone and keys.

I think there's one too many commas on this.

What happens when you type that number out on your phone?

Grab a phone and bring up the dialing screen. Each number button will have letters associated to it. If you match the numbers, and the number of times they appear, to the letter on the dialling pad you'll be able to spell out a number - 333 = F, 666 = O, 88 = U, 777 = R.

The pattern on this flyer looks an awful lot like the pattern on the Art Fest ticket. Could they work together?

The dotted lines are for cutting. Once you’ve cut along them, does the ticket look like an arrow to you?

Match the patterns on the ticket to the poster. What do they point to?

You’re going to need an order to put the numbers in. Take a look at the logo on the poster does it appear on the tickets?

Cut along the dotted lines of the Art Fest ticket to turn it into an arrow. Start with the side of the ticket featuring the red shape and match its pattern to the corresponding part of the painting on the poster. The arrow points to the number 7. Next, turn the ticket over and match the pattern on the side featuring the yellow shape to the painting. This points to the number 6. To work out which order the numbers go in, look at the Art Fest logo. It shows the red shape followed by the yellow shape, so read the number from the red side first, followed by the number from the yellow side. This gives you 76, so the answer is 76.

There’s not much on this business card. Just a website really.

The words in bold must be some sort of clue. Is there a hidden link on this site?

You might need a keen eye to spot the way to the answer. Is there anything on the website looking back at you?

The words in bold on the website say: “Sometimes the smallest detail tells you where to look. What we notice first is not always what matters most. The eyes usually know more than they let on.” Click on open eye in the painting of the face. This will take you through to a hidden page the reveals the number 32. The answer is 32.

There’s more to Nina’s email signature than just her contact details. Have you noticed anything unusual?

The letters in each pair follow the same pattern - look at their positions in the alphabet. Can you work out how they change?

Can you find an email with a code given to you? Use what’s you’ve worked out on this code.

The email signatures contain pairs of letters that show you how the cipher works, including B=Q, C=R, L=A and S=H. In each pair, the second letter is 15 places further along in the alphabet than the first, looping back to A when you pass Z. For example, counting 15 letters forward from B gives Q, and counting 15 forward from L takes you past Z and back around to A. This same rule can be used to work out the translation for every letter of the alphabet. Now find the transfer code in the email: PTRSE. Using the cipher, P=E, T=I, R=G, S=H and E=T, which spells EIGHT. The answer is 8.

Take a close look at both sides of the token. Have you noticed that the same decorative patterns appear on each side, but arranged differently?

The base of each pattern is the same, but the shapes at the top are different. Compare the row of patterns on one side with the patterns around the edge on the other.

What letters sit inside the matching patterns?

Look at the patterns on both sides of the token. On one side, they are arranged in a straight row, while on the other they run around the edge of the token with letters between them. The base of each pattern lis the same, with the top changing. Take each of the three patterns from the straight row and find its exact match around the edge. Then take the letter associated with each matching pattern. The letters spell ONE, so the answer is 1.