Critique my idea- first attempt at writing ( Fantasy [mythology,folklore])

Hey guys,

Okay so I've been chipping away at this for a while and I have no idea if the core idea actually holds up or if I'm too close to it. Would love some honest takes before I sink more months in.

It's a thriller, sort of fantasy/sci-fi blend, set in India. The lead is Dr. Ishani Rathore, a forensic pathologist at a classified government forensics institute. The book opens with a case that shouldn't be possible- bodies recovered from high altitude, frozen, but with these crystalline lattice structures grown into the lung tissue. Nothing in the literature explains it. The deeper she digs, the more it ties back to a buried government project and a region around Mount Kailash and Lake Mansarovar.

That's the spine. The part I'm nervous about is the other layer. Alongside the case, Ishani starts experiencing things she can't rationalize and a dream that won't leave, a pendant that warms when it shouldn't, a pull toward the mountains she can't explain. She's a scientist and a doctor, so her whole instinct is to find a rational cause, and she keeps almost managing it. The book is basically her losing that argument with herself, one small undeniable thing at a time.

There's a slow-burn romance with an intelligence agent assigned to the same investigation and both of them guarded, neither great at letting anyone in. And the appearance of this very normal person in her life somehow pushes her in dept about the secrets of what was always a folklore.

It ends with her catching a glimpse of something about her own past that recontextualizes everything, but I'm trying not to spoil that beat too early in the book.

My main worries: does the forensic-mystery half and the supernatural half sound like they belong in the same book, or like two ideas duct-taped together? And is "scientist slowly forced to believe" too well-worn? Like this is one idea which I feel hasnt been explored alot and with the mysteries behind mount kailash which even many scientists are wondering about, does this seem like an idea that would run with people?

Be brutal, I'd rather hear it now.