Why can't I get past the Eye

Hint 1 of 4:

You must have the four keys to proceed to the Book of Thoth

Hint 2 of 4:

You must solve: Three Ships, The Humbug, Justice, The Hermit

Hint 3 of 4:

Each of the above yields a key when solved

Hint 4 of 4:

You must repeat the actions you took to get keys 2,3,last for the Book