The 76543 Cipher

The 76543 Cipher:

In chapter 2 of the Book we first found a string of text that went:

pof ujvwnf vhyhu jswciX ymj 76543 jpwoly. vn Xwn pybvodc jzf mdv bhg.

By rotating each word in this string down by -1 rotation less than the previous one you get:
One should never forget the 76543 cipher. If one forgets you are out.

The chapter then details the rules of what we assume is the 76543 cipher.

In ; a b ;
a is i and b is ii
a is b and b is d

The solution to this was that each position in a string has a number, so in 'jiefwa' the letter f would be numbered 4 and a would be numbered 6. Each letter's position in the string determines how many rotations that letter has undergone(see: the caesar cipher), so decoding it would mean rotating back by that same amount of rotations. Important: using this cipher requires that you count spaces as characters as well, but the spaces can not be rotated.

Applying the cipher to the string
'jh ssc aXwgvv iXzc iia gr sgdhd aw cemeh Xzc jdhdphmbih.'
Returned
'If one solved then one is ready to start the pilgrimage.'

And so we were.