Echo in the Skull, 1959: Sometime in the late 1950s, Sally Ercott awakens from a drunken stupor in a filthy room in a sleazy boarding house on Mamble Row in the Paddington section of London.

She is destitute and suffering from amnesia and the proprietors of the house, Arthur and Bella Rowall, eagerly await the day when she agrees to work for them as a prostitute.

As they wait for Dr. Gospell, Sally and Nick discuss her nightmares and infer that they seem like actual memories of girls and women dying on alien worlds.

Leaving Bella bound to a chair, the men hurry to Nick's apartment to prevent Arthur from kidnapping Sally.

Relying on her acquired memories, the waking nightmares that had plagued her, Sally tells the men that the creatures, called the Yem, are sentient parasites that have learned to propel their spores into space, where they ride the radiation winds of the stars to spread their kind across the galaxy in an act of panspermia.

Now that Scotland Yard has been alerted to the danger all of humanity can be warned and the Yem attempt to take over Earth can be thwarted.