Recent casualties involve some strange deaths – one, Hay Connor, died after landing while he was still in his plane, while another, Myrtle, was discovered with his head missing.
Joyce-Armstrong speculates that the answer to these deaths may be the result of what he calls "air-jungles": There are jungles of the upper air […] One of them lies over the Pau-Biarritz district of France.
It is then that he learns that his speculations are right: entire ecosystems (air-jungles) exist high in the atmosphere, and are inhabited by huge, gelatinous, semi-solid creatures.
After going through a flock of animals superficially resembling jellyfish and snakes, Joyce-Armstrong is attacked by a more solid-looking but amorphous creature with a beak and tentacles, from which he narrowly escapes.
The aviator writes he will be going up again to the air-jungle to bring back proof of his discoveries, but here the fragment ends, save for one last sentence which reads: "Forty-three thousand feet.