光の差さぬ暗い影 vaguely understanding this line

Question

I started a light novel and I knew I would see more of formal writing and I have this part that I only understand a little. The subject is about shadows, which relates to supernatural beings (this story has a character that fights with these kinds of beings).

I have this small description of the shadows:

ひそやかに舞い狂う黒い影。

光の差さぬ暗い影にうごめく、怪しい気配。

It is the second line that I do not understand well, like I get the gist, but perhaps I am understanding in a wrong order. First of all:

光の差さぬ=光の差さない

Would this be correct, like the modern way? And if so, I still don't get a clear picture, how should I understand this? I think my interpretation is wrong, but I will try and I'm breaking down the sentence:

光の差さぬ "where light does not shine"
暗い影 "dark shadows"
うごめく"to squirm" or '"to stir"
怪しい気配 "weird sensation" or "presence"

"Towards dark shadows where there is no light shining, it stirs and gives (you) a weird sensation".
Does it make any sense at all? I think I am wrong, so can someone please help?

Answer 1

光の差さぬ=光の差さない

Yup, this is correct. Please see the 「ぬ」 section here, but basically it's just an old fashioned negation. I mostly see it in relative clauses.

As for:

光の差さぬ暗い影にうごめく、怪しい気配

You have translations of all the pieces done pretty well, you just didn't put them together quite right. The whole thing looks like one big relative clause to me, for something like

An ominous presence writhing in the dark shadows where light does not shine.

光の差さぬ暗い影 is just "dark shadows where light does not shine", with 光の差さぬ and 暗い both qualifying 影. Similarly, 光の差さぬ暗い影にうごめく is all one big relative clause that qualifies 気配, which 怪しい also qualifies.

Qualifying one noun with both an adjective and a relative clause can look a little awkward at first, but it's not that uncommon. A simpler example might look like:

草を食べる大きい牛

A large cow that eats grass