Hekkus is trying to sell the secret of immortality for instructions on how to create perfect counterfeit money, but Gersen ends up with the latter process.

When a beautiful, young woman named Alusz Iphigenia Eperje-Tokay, who claims to be from the legendary lost planet Thamber, discovered that Hekkus wanted her, she sought refuge at the only place she could think of that could not be pressured into surrendering her to him: Interchange.

During his investigation, Gersen ransoms Myron Patch, an engineer who built for Hekkus a walking "fort" in the shape of a dnazd, a many-legged monster native to Thamber.

Gersen has also printed his fake money using ink that will fade away in a couple of weeks, thus robbing Interchange and Hekkus of a vast fortune.

Gersen disables the machine, using a secret device he had had installed, and takes its crew prisoner, observing that one of them, Franz Paderbush, resembles Billy Windle.

He returns to the Oikumene accompanied by Alusz Iphigenia, promising to send ships to bring Thamber back into contact with the rest of humanity.