The patient is prepped for surgery, lying horizontal on the operating table, staring up into a vastness of bright light.

The anesthesiologist readies the syringe and flushes the drug into the IV line. She watches the patient’s face and posture slacken as they drift out of consciousness. And everything fades to black …

It’s an intimate moment, says Dr. Marie Heaton, a moment of transferred power.

But what if the patient doesn’t wake up?

Heaton’s an anesthesiologist in Bainbridge authoress Carol Cassella’s debut novel, “Oxygen,” in bookstores July 1.

Heaton’s at the top of her profession when an 8-year-old patient dies under the knife and she is left staggered in the aftermath. Sounds like a real downer on the surface, but it’s actually rather insightful. And it’s said to end with a surprising conclusion.

The real hook, Publisher’s Weekly says, is Cassella’s in-depth knowledge of the complex inner workings of the health industry. She’s spent 25 years in the medical field, currently an anesthesiologist/freelance medical writer in Seattle.

What’s more, she’s the mother of two sets of twins born 15 months apart.

And she writes novels.