The letters are mainly from publishers of various science fiction magazines either accepting or rejecting various short stories that Wyndham had submitted. The titles covered are include

• The Tyburn Tree
• The Cathedral Crypt
• Venus Adventure
• Man Who Returned
• Conquest of Space
• The House at Hardcase
• Invisible Monster
• Exiles on Asperus
• Jetsam of Time
• The Stare
• Martian Blood
• The Third Vibrator
• Puff-Balls
• The Convict
• Sub-Sahara
• The Moon Devils
• Lone-Handed
• Foul Play Suspected
• The Secret People
• Perfect Creature
• Murder Means Murder
• Death Upon Death
• Judson's Annihilator
• Burn That Body
• Trojan Beam

Most of the letters are from the editors of Wonder Stories, Astounding Stories, Strange Tales although there are some letters from the Daily Mail, The Express and Mills and Boon. There are also some receipts for stories that were submitted and later published.

Some of the letters give lengthy reasons as to why the story had been rejected. In a letter dated 26 April 1932 the editor of Wonder Stories wrote

the chief difference between weird tales and science tales is that the former make no pretence to any scientific explanation for what has occured...to be acceptable (as a weird tale) your story should have a little more development and there should be an explanation given where these monsters originated and how. That explanation should be something original, and not the hackneyed business of a scientist experimenting with life and finding that the creatures had gotten beyond his control.

The editor of the same magazine in 26 February 1934 said

There is one very severe error in your story. If the man was in the other dimension and his hand in this, his hand could not defy gravity and remain in the air. It would fall to the floor of the laboratory, and he would probably bleed to death from loss of blood from his severed wrist in the other dimension.

Wyndham collected together letters relating to Foul Play Suspected, please refer to Wyndham 1/1/2