I was definitely going for a subterranean terror, a fear of something you cannot see but is ever present. I'm glad you enjoyed it.

As for your question about writing a continuation - yes and no. I've tried serializing stories before with limited success. I've seen a lot of people on Steemit do that and it seems like a sensible way to build a readership, but in my experience interest seems to drop off almost immediately after the first installment, if indeed it generates any interest at all. I can also understand that - it's a little daunting to see something labeled "Part 7" and realize you'll have to read 6 other parts first if you haven't been followed all along.

Right now I'm taking a different approach. If you look at some of my previous stories, you'll see they have some overlap in characters or themes or both. In a couple cases I've written about the characters when they are adults. Rather than execute a planned serialized story, I'm taking a more experiment inductive approach. Expect to see more stories about the deep and about Sid, his brother, and their friends, but maybe not as a part of a single cohesive whole. At least not yet.

Someday I hope to assemble the various stories together into a big one. Right now I'm satisfied to put together somewhat self-contained chunks that are allowed to go in whatever direction seems appropriate without constraining them by a larger structure. Hope that makes sense.