![[Welcome to Sensei's Library!]](images/stone-hello.png "Sensei's Library")
"Then Black plays on the 2-1 and White throws in to make the direct ko. Now White can use the local threat at 6 to effectively take the ko first. (Note that Black may now have ko threats, starting at a."
from here I lost you because there is no 2-1 to play
The text flow was confusing. The text "8 takes the ko" was meant as a clarification of the diagram, but appeared in the main text before the line you quote, thus confusing what moves are being talked about. I've moved it to its proper place, hope it is clear now!