Cipher

Well, I don't get the "simple" pattern...
I tried some patterns, but no one is right.
Help please?

Seems not many people have problems with this one, but I'm currently stuck here.
Whose idea was what? The crystal, the mirror, or something else?
Feel that I'm lack of some common knowledge...

emiliapercival wrote:You should have two hints already.

How do I combine the TZ thing with those numbers will I get letters? Really confused. Still think I need to find another hint...

I can only get one hint from the title, the one which is implied in earlier replies.
Been stuck on this level for a whole day...
Just don't understand what kind of decoding is needed...
Would anyone kindly PM me please? Thanks a lot.