In February 2024 I read book one of Haru by Joe Latham (or Haru 1: Spring). In August of 2024 I read Haru Book 2: Summer still by Joe Latham. Both were read via an online reader copy but I was thinking I would purchase copies of both when book two came out. However, it is not due until October 2024 and I am glad I did not wait.
This is because Book Two is much darker than Book One was. Things are more layered and more happens simultaneously. It is busy, crowded and because of the layer and new characters that are added it was a smidgen confusing at times. We learn more about the villain Blight, but not as much about Haru and their friends. However, new questions and problems arise and I need Book Three for answers! Of course, you should read Book One first, and when book three comes out (currently no date) read them again. Things pick up where we left off in one and I had forgotten several things so I had to stop and say, “Oh yeah. The oracle.” and “Okay, why can’t Haru fly?” The humans are missing in this world, but their remains (buildings mostly) still haunt the land. I am not sure if they are really necessarily important to have mentioned (as the animals have adapted humanistic traits: going to school, bullying, having adventures and therefore are the “humans”) but maybe in book three we find out more. 
This time we are dealing more with evil and some of the depression of one of the other characters. We are also seeing the contrast of fear and bravery. Things are written as a younger Redwall (and/or fantasy) but it has serious themes which are probably meant for an older audience.
A quickie note on the art. The cover pretty much tells you what you need to know about things. Colors and details are minimal, the browns and reds are muted, but are the focal points. Things can be “nice” at times, but not usually. If this was a movie the illustrations would be the “spooky things are happening soon” effect.