Going back to the 1 shell, the rules still apply.

1.  The reveal shell is the product of the proceeding prime numbers, 1=1.
2.  Keep skirting anticlockwise around the shell, and the next prime number is 2, 1 shell, showing breakdown at 4 .
3.  Square the next prime number, and you get the limit the system works to, 2^2=4.