I think I found it while I was on Mission 16, I went through that labyrinth. My previous mission was to unravel the secrets of Staff of Hermes, but then I suddenly bumped into this secret mission. Anyway the mission is to get a blue orb that's floating in the air. I tried so many ways to get that orb, but I just can't. If anyone's passed this, please let me know how to get it.

Thanks in advance!