On April 1, 1965, the BBC aired an interview with an inventor who claimed his television could transmit smells, chopped onions and brewed coffee on air, and hundreds of viewers called in swearing they could smell them. The prank worked because it tapped into a very real, decades-long industry obsession. This deep dive traces the history of olfactory cinema from an 1868 London stage show misted with Rimmel perfume, to a 1906 Pennsylvania theater manager pointing an electric fan at rose-oil-soaked cotton, to a Boston manager pouring a full pint of lilac perfume into the ventilation system in 1929. It explains the biological barrier of olfactory fatigue and why lingering molecules turned theaters into muddled, days-long stinks that even made Walt Disney abandon plans to scent Fantasia.

The episode then follows Swiss inventor Hans Laube from hi ...