To convince her scientific colleagues of the value of the invention of the Ferengi Dr. Reyga, Bev invited them all to the Enterprise for cookies and one-upsmanship.
Reyga's metaphasic shield can protect a shuttle within a star's corona, but he needed resources to develop it. He was a weird Ferengi: the only opportunity he sought was to be acknowledged and respected. What a jerk! No wonder these Federation types turned on him.
Something went wrong and pilot Jo'Bril died. Beverly's autopsy was both non-invasive and inconclusive. His Takaran internal anatomy is distributed throughout the body in a way she'd never seen. He's not even decaying right!
Disappointed and angry, Reyga was found alone in Lab Four seemingly dead by his own hand. His family refused to allow autopsy: by unshakeable custom never mentioned before or since his body must be buried without violation. (Even non-invasive scanning? Nothing in this episode makes it sound like Reyga's valued enough by Ferengi standards to become a Corpse Collectible like the Nagus. So why no autopsy? It's not an insight into Ferengi Culture so much as a plot device.)
Full of "Suspicions", Detective Beverly interviews the other scientists. Her accusation against Kurak does not go well: she throws the nosey doctor across the room. But out of guilt or ordinary Klingon rage? Maybe SHIP'S SECURITY should be doing this... Nah. Where's the sense in that?
Beverly autopsies Reyga anyway, turns up nothing and is removed from duty. Riker urges her to stop making things worse. Nurse Alyssa Ogawa helps her continue to investigate, otherwise known as making things worse. (It looks like friendship and loyalty, but if you think about it, once Beverly's fired maybe Ogawa gets more scenes!)
Crusher steals Reyga's shuttle to test the sun-shield herself. It works fine. She is set upon by Jo'Bril: he's stopped hiding in the morgue drawer and started hiding in a foot locker. He can control his body at the cellular level, faking death. With Crusher's demise, he can take the technology back to Takara and weaponize it. Without attempting to stun him, Bev phasers a hole through his chest. When this doesn't work, she disintegrates him.
Way to kill, doctor! Here's your job back.