A God of Wire & Ash by Gregory Westlake

A realm of magic. A creator worshipped as divine. And a screaming laboratory that shouldn't exist.

To the inhabitants of Fabernburg, their world is a sacred sanctuary. They revere FABER, the ancient architect who moved upon the desolation of a ruined earth, who facilitated refuge to other beings fleeing demonic horrors. It is a world of mythology, ancient order, and absolute faith.

Then, Cassie wakes up.

Armed with a physicist's understanding of reality, a cynical edge, and an absolute refusal to believe in magic, she finds herself stranded in a timeline that defies all scientific logic. But Cassie knows one thing for certain: gods don't leave behind failing containment systems and blaring alarms.

As dimensional rifts begin to tear the fabric of this sanctuary apart, Cassie's search for the truth collides with the realm's defenders, including a seasoned Field Marshal of the Kingdom Forces and a formidable Elven Fire Mage. To survive, she must untangle the hard science hidden beneath their religious myths. Because the long silence is ending, and whatever is tearing at the edges of reality is coming for them all.