I didn't care for this one. I was intrigued by some of the idea, especially the world inside the coat, which was nicely foreshadowed by the eyelid window shades at the beginning, but there was no real plot to it.
I found the flashback section with Lavender disorienting--I wasn't really clear that it was Bumplethorn himself until the flashback was over, and that was a looong flashback, so I spent most of that time pretty confused.
Even before that, there were so many weird details that were never really fleshed out, and so it seemed like just an attempt to heap up weirdness and hope that it was mistaken for a story. Why are florists the only ones who can deal in blood? What's the point of tradiing blood for water--the blood contains water so you're only going to get more dehydrated while you give away valuable iron and other vital elements.
And worst of all, is the point-of-view withholding. Although the title combined with the eyelid windowshade at the beginning implied the secret behind his coat, that needed to be fleshed out MUCH sooner. That is an incredibly relevant information that is left out until much too late. He's staggering around the city, trying to find any source of water, heads into the flower shop, and offers to sell an entire world in order to get water... all of this while he has RIVERS flowing inside his COAT, which apparently all he needed to drink was to have a glass. You can't get a much more relevant detail than that, and so the POV should have shared it with me--but I suppose that would've removed the only tension in the main narrative, false as that tension was.