Realistically, Book 2 of this series (Edge of Darkness) won't be out for at least several months. After my last story (Charlie), I decided to write future stories in their entirety before releasing any chapter of it to the public.
And although I've started writing Book 2, it is VERY FAR from being completed at this point. Book 1 took me several months to write as I do this in my spare time rather than having it take up most of my time.
Also, the two mini-novels (Spirit of Vengeance and the one I intend to write between Book 2 and 3) have similar formats such that they happen simultaneously with events in the other books while involving other main characters which will serve as important secondary characters to the rest of the story.
So yes, where the mini-novel and the main books intersect, it might feel like there is a huge cliffhanger (as you might see here) but it's mostly because the next book will pretty much pick up where the mini-novel left off. So think of the "next chapter" being in Edge of Darkness rather than the story just ending.