Zoom in on them to find a handy little puzzle. Isn't it lucky for us that the culprit didn't just use standard handcuffs that can't be unlocked without a key?
As Nancy says, the rings spell something. The goal here is to spin the rings until all of them spell out words related to Greek myths. Read to the end of this hint for a screenshot.
One way to tackle a puzzle like this is to realize that if you get one word right, all the rest of them will probably be right. So you don't need to actually solve all the words. (The master puzzle is harder, though.)
With that in mind, try thinking of a likely word that's 5 letters long (or 4 and 5 for masters) and see if you can find it here.
Unfortunately, Nancy no longer has any of her reference books, so you'll have to rely on your memory.
The middle ring doesn't turn, so you might start looking for words that begin or end with those letters.
You should also be aware that some of the letters repeat. If you've spelled a word and the chains don't unlock, look for one of the letters to appear somewhere else on that ring.
Totally stuck? Here's half a hint:
One of the words in the amateur puzzle is "Hades." One of the short words in the master puzzle is "atah."