FULL SPOILERS allowed in this thread.
This is the second part in the second graphic novel trilogy for LoK, and deals with the Earth Kingdom's transition to democracy. It will release November 12th mass market and in comic stores the next day. This book was written by Mike with art by Michelle Wong.
There are several main comics which take place shortly after ATLA. They build towards LoK and answer some questions left at the end of ATLA. Check the FAQ for more details.