Remember, if you haven't used our clues pages yet, check out the instructions here to learn how they work and how to best utilize them. 

Card 3A.jpg

Hint 1

What's an alternate name for a parrot?

Hint 2

The word 'psittacines' might be what you're looking for...

Hint 3

Just need to find the pattern to make that word, now.

Hint 4

This puzzle has its ups and downs.

Solution

This is an alternating +1 -1 cipher, so AAAA would become BZBZ, for example.
The plaintext reads: "I have tracked the location of the stolen Vermeer painting The Concert."

Card 3B.jpg

Hint 1

There's some interesting text going down the center of the card.

Hint 2

That text may not look colorful, but it is.

Hint 3

I think you'll find those are hex codes for different colors.

Hint 4

So you have two pairs of colors that you're looking for...

Solution

Final Solution: The hex codes tell you to find purple/green and also red/black. So you want to locate every instance where those colors are paired in that order.
The plaintext reads: "I bribed the owner of the facility to let you in. His name is Helmut Schultz."

Card 3C.jpg

Hint 1

The stamps are only your map, not your destination.

Hint 2

What could they be referencing?

Hint 3

Have you used your main paragraph yet?

Solution

Final Solution: Using the stamp numbers to indicate line/word, you get the plaintext: "Cube Smart Self Storage."

Card 3D.jpg

Hint 1

If you haven't figured out your stamps yet, you may want to go back to those.

Hint 2

If you know what the stamps are telling you, then the information in this paragraph will help you find a specific location.

Hint 3

If you know what you're looking for, then you know where it was stolen from. If you haven't solved the front of this card yet, you'll want to do that first.

Solution

Final Solution: The painting in question was stolen from the Gardner Museum, and the closest Cube Smart is at "968 Massachusetts Ave, Boston."