Jason’s biggest fears

Hello!

Her dead body flickered in his mind, his nails that he took so little care of were covered in her blood, for they were too long and too dirty.

This is a comma splice because these are two complete thoughts joined by a comma. The description of his nails is also a little confusing. His nails being long and dirty wouldn't be the reason they're covered in blood, though I think you mean that the blood has become trapped underneath them because he doesn't look after them.

You could separate the image of Branwen's body from the physical evidence still on Jason as well. I think the blood under his nails could be a really unpleasant detail if he keeps noticing it while trying to sleep. Does he pick at it? Has it dried? Is he afraid to wash it away because someone might notice the water?

What was he going to do? He couldn’t hide her in Mr. Glutten forever. He had to hide her somewhere else…but where?

The questions work well because they keep us in Jason's anxious thoughts, though you could show a little more of what he fears will happen. Is someone likely to visit the shop and discover her? Details like that would make the setting feel more real and urgent. At the moment Jason says he can't leave her there forever, but I don't know whether he has hours, days or weeks before she's found.

In his childhood, Jason not only spent his spare time making toys, but reading up on magic as well.

The "not only" construction should be balanced, so it would be "not only making toys but also reading about magic."

This information also arrives a little conveniently. Jason notices a wax doll and immediately remembers that he studied magic as a child, which happens to provide a possible solution. I think it would feel more natural if you had already hinted at his interest in magic. Perhaps there are old books in the workshop, symbols carved beneath the dolls or an earlier failed experiment he remembers. It's difficult to understand why magic comes into the picture here.

"Reading up on magic" also sounds quite casual. If he genuinely believes he can trap a soul, I think we need a stronger sense of what sort of magic he studied and why he believes it works.

If souls were real, then he could invent a tool that would be able to trap Branwen in a doll! He would be safe!

This feels like a very large leap in logic. Even if Jason traps Branwen's soul inside a doll, he still has her physical body hidden inside Mr. Glutten. Trapping her soul wouldn't hide the evidence of the murder unless the magic also moves or transforms her body.

Jason got up from the narrow bed and pulled on the string light.

I think this should be "pulled the string to turn on the light" or "pulled the light's string" instead. As written, it sounds as though the string itself is a kind of light. The narrow bed is a nice detail though because it suggests that he sleeps in or near the workshop rather than having a comfortable home elsewhere. I would describe what the light reveals when it comes on. This is a good opportunity to properly show the shop and Mr. Glutten.

***

This is very cool! The biggest thing that needs clarifying, though, is the relationship between Branwen's body and her soul. Jason begins by worrying that her body will be discovered, but his solution is to trap her soul. Unless the magic will also conceal or transform the corpse, these feel like two separate problems. You may need to make it clearer why Jason believes the doll will keep him safe.

I'd also like a stronger sense of Jason's emotions. I know he can't sleep and wants to avoid being caught, but I don't know whether he feels guilty about killing Branwen. This might be my unfamiliarity with the story, but I'd like to see more!

Cheers! Thanks for sharing!

Lipton