Biologist Ella Al-Shamahi investigates why whale strandings along the UK coastline have been rising, joining a team performing a necropsy on a 40-foot sei whale that washed up near Edinburgh. Cameras follow the dissection in detail, with pathologists cutting through blubber and organs to look for signs of ship strike, entanglement, disease, or starvation, while Al-Shamahi presses them on what each finding actually proves. The film widens out from that single carcass to the broader pattern of strandings around Britain's coast, bringing in researchers who track sonar use, shipping traffic, and changing prey distribution as possible drivers. Archive stranding data and interviews with marine scientists build a picture of an ocean under more pressure than it looks from the shore. The sei whale autopsy anchors the whole hour, giving the science a concrete, sometimes visceral, center rather than letting the investigation stay abstract. It ends without a single tidy villain, closer to a list of suspects than a verdict.