When pre-med student Briella Fan encounters three dead bodies by the woods, she never thought she would wind up hiding
the suspected perpetrator: Dusk, a n assassin-made-fugitive from another world. [there's a lot crammed in this sentence, this is just a suggestion to make it a little more succinct. Of course, if you cut his name and mention of him being an assassin, then you'll want to find a place to put those details back in.]
She just wanted to help someone in need, and [the fugitive,] Dusk
pled his case well enough. He convinced her that he’s innocent, and just needs to learn the ins and outs of her town until he can get back home. ['innocent' seems like an odd word to use here... and why does he need to go to the town if he's from out-of-world? Something more concrete and convincing would make more sense and make your MC read less gullible. I.e. convinces her that he was lost in the woods and has never seen the dead bodies before.] From this, a cautious relationship bloomed. [flat and, again, unconvincing. Your pre-med student seems far too quick to dismiss three dead bodies.]
[The third paragraph mostly reads like telly, wordy narrative. Making suggestions to trim and turn it into information for a query]
soon comes to regretted her decision after an poisoned arrow narrowly missed s her head. [take out details she can't possibly know, keep it in past tense, and maybe consider rewording the sentence to introduce the plot complication rather than the arrow: When a bounty hunter appeared...] When she demands answers, Dusk finally comes clean. He admitted to being an assassin who fled his world for killing a Duchess. And Zeyvn, a bounty hunter from Dusk’s world, has followed him, intent on bringing Dusk back in chains, or even better, headless.[nothing technically wrong with this but you could cut it] Accusing [poor word choice; he's not accusing, he's convicting] Briella of guilt by association, Zeyvn will take her instead, dead or alive, if she won’t give Dusk up. [the rest of the last sentence is awkward because it switches to Zevyn's POV when everything thus far has been in Briella's. Also, it implies one of two things: 1. Zevyn is ineffectually yelling this condemnation at them in the woods like a child or 2. He's already captured Briella and is resulting to douche-baggery because he's bad at his job... A third option... I read too much between the lines...]
Dusk assures her they’ll get through this together. [this leads me to conclude option 1] But now, she isn’t sure she trusts the man who knowingly got her into this mess. Yet, handing Dusk over could get her imprisoned in another world, or killed. One wrong move could mean the death of her medical future, or worse yet, herself. [her medical future, thanks to the above context, is a very weak and unimportant stake compared with 'killed for aiding and abetting'... this whole last paragraph is riddled with redundancies.]
NIGHTSWORN is an adult contemporary fantasy complete at 98,000 words, told from multiple points of view.
Also, I just realized that I've no idea how/why/where the 'from another world' part matters to this query.
Ok, since I mostly shredded it above, here's a possible rebuilding:
When pre-med student Briella Fan encounters three dead bodies in the woods, she never thought she would wind up hiding a fugitive.
She just wanted to help someone in need and the fugitive, Dusk, convinced her that he was lost in the woods and never saw those bodies before. When a man appeared, firing arrows, the two fled to safety. Angry and confused, Briella forced the truth from Dusk: he's an assassin on the run for killing a Duchess. The man was a bounty hunter who wants him dead or alive and will happily kill Briella to get to him.
Briella isn't sure she can trust this lying assassin, but the bounty hunter who would imprison or kill her for unwittingly helping him isn't any better.
If nothing else, take it as a suggested way to cut the fluff. If there's any sort of romance brewing between Briella and Dusk, it's so far between the lines as to be invisible. Bring it out more if its pertinent, otherwise don't.
Final thought: this would also have a genre tag of 'hidden world'... I just have no idea why it would matter to the query. Plot and setting, sure. Query, not so much.
Hope that helps!