Answer:
What letter comes next: O T T F F S S ?
As a whole, I am both safe and secure. Behead me, I become a place of meeting. Behead me again, I am the partner of ready. Restore me, I become the domain of beasts.
A precious stone, as clear as diamond. Seek it out while the sun's near the horizon. Though you can walk on water with its power, try to keep it, and it'll vanish in an hour.
It cannot be seen, it weighs nothing, but when put into a barrel, it makes it lighter.
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around
What covers its face with its hands, speaks no language, yet most known what it's saying?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?