When a priceless koi fish is found dead, the killer isn't just fishing for compliments.

Dr. Aris Thorne and Mia Rodriguez are hired to inspect the prize possession of a reclusive art collector: a legendary koi fish valued at a million dollars. But their visit takes a grim turn when "The Golden Dragon" is found dead in its pond. The police dismiss it as an aquatic tragedy, but Aris and Mia quickly realize the fish was poisoned with a rare toxin.

Their investigation plunges them into the murky world of high-stakes art forgery and obsessive collectors. The suspects are as cold-blooded as the crime: a rival collector who would kill to own the fish, a gallery owner who sold a forged painting to the victim, and the victim's estranged son who resented his father's lavish spending on fish.

As Aris deciphers the silent clues from the other koi, Mia works to untangle the web of lies among the humans. They must expose the forger and the killer before another life, human or otherwise, is claimed.