Now I'm confused

[catalyst2]

Then again, it doesn't take much to confuse me these days! On Kelley Armstrong's discussion board, she says she is writing AtS: Aftermath but in a separate arc to Brian Lynch. Does that mean she will write one arc and Brian will write another and they are totally unconnected? Or they are both part of the same continuing story? Or they are arcs for different characters but happening at the same time? Or .....?