While visiting the Monument to the Eighty in Chasm City, Richard meets his old friend Roland Childe, who has been presumed dead for over a century and a half.

Childe takes Richard back to his home, and reveals that he is assembling a team to tackle a curious artificial – alien – structure found by probes sent out secretly by his family ages ago.

Remains of the previous human explorers to visit the place lie around – supposedly they belonged to another Ultranaut crew led by a captain called Argyle, whom Childe's probe interrogated during his dying moments to gather information about the Spire.

To deal with the Spire's puzzles, the team submit to more and more cybernetic and artificial aids by Trintignant's hand, which eventually culminate with Childe and Richard resembling nothing so much as diamond dogs, with artificially-accelerated consciousness and an advanced grasp of mathematics.

In the end, Richard, faced with the sheer temptation and curiosity of the Spire, secretly slips away and hires the lighthugger Poseidon to take him "somewhere".

When Naqi finally catches up with him, he reveals that the "scientists" were in fact members of a lunatic organization whose dead leader had stored his thought patterns with the Jugglers on Turquoise, and that they intended to incorporate him into all of the many-thousand strong army of followers that were waiting in orbit on the Voice of Evening.

The agent says no one knows where the toxin originated, though he mentions several rumours, one of which indicates that it had been found in the top of the Blood Spire from "Diamond Dogs".

However, it transpires that the Jugglers had developed a resistance to the toxin after the first vial that had been slipped into a contained portion of the Moat, and the overall collective is unharmed.

During their hibernated sleep on the way to the planet, the characters in Diamond Dogs share dreams which reference the novel Rogue Moon by Algis Budrys, and the films Cube and Raiders of the Lost Ark.

[1] Alastair Reynolds travelled to Chicago to have a discussion with fans about the novella, science fiction, and astrophysics, before the February 25th, 2017 show.