Roots: The Birds (the Doctor refers to Daphne Du Maurier), Battlestar Galactica, the incidental music recalls the theme from The Twilight Zone. The Doctor and Evelyn paraphrase from Macbeth ('no eye of newt?' 'no wing of bat...'). Mordecan refers to The Pied Piper of Hamlyn.
Intertextuality: The idea of the Doctor's costume causing distress to a 'chameleon' [i.e. Galyari] may be based on a popular quip of Colin Baker's regarding the same costume.
Technobabble: Galyari surveillance drones have photo-reflective shells. General Voshka and his followers were exposed to neural radiation.
Dialogue Disasters: 'Steady as she goes and pay attention to the Clutch' (groan!)
Dialogue Triumphs: Evelyn to the Doctor: 'A happy accident? I sometimes think that's what you are.'
'Show us your best side.' 'Trust me - he hasn't got one.'
'We can't always reap what we sow, but in the end it's what we sow that matters'
Double Entendres: 'I'd hoped I was still good for a spot of bedtime reading material.'
Continuity: The Clutch is a fleet of migrating interconnected ships. Some ships at the centre have not moved position for centuries. It is inhabited mainly by the Galyari, but also by hundreds of other species. Many of the ships are not hyperspace capable, so the fleet moves slowly. The Clutch is ultimately managed by the Galyari's computer 'Traffic' and a Galyari Orchestrator. They provide security forces.
Physically the Galyari are reptilian in appearance (though descended from avian species) with chameleon-like opposed eyes. They have extremely sensitive vision.
They shed their skins at regular intervals, during which time they are helpless, a state referred to as growth sickness.
The Galyari dread the Doctor, whom they also know as 'the Sandman' due to a belief passed down through generations (see: 'Untelevised Adventures'). They store knowledge in 'shushkubra' - memory eggs, which are grown aboard the Clutch from discarded Galyari skins. A shushkubra is a living repository for the Galyari, which are cultivated onboard the Clutch in a bio-fusion chamber. It's like a collective brain without intelligence, designed for storage, a sort of biological databank. Galyari shared an intuitive collection with it. It's intended to house the entire experience of Galyari DNA and grown from such DNA. One is put on every colony the Galyari visit. The Clutch is presently nearing the world they call Galyar.
When the remains of a destroyed shushkubra come into contact with Galyari people, they undergo mutation. Galyari have extraordinary eyesight, however that sensitivity finds intense colour combinations (such at the Doctor's coat) painful. In the past, they had a chameleon-like ability to blend in with their surroundings. They have a habit of getting into the arms trade, despite the Doctor's work to the contrary, and maintain trade links with humans. They have an almost religious fascination with birds, due to their shared ancestry.
The Doctor lies upon occasion when necessary.
Untelevised Adventures: Over one hundred thousand years ago, a Galyari force lead by General Voshkar attempted to retake one of their colony worlds (named Galyar by them, and regarded by them as their home world), inhabited by the Kooskaru. There they encountered the Doctor who set himself up as the Sandman figure and banished them from all worlds. He also destroyed the shushkubra holding the Galyari race memories. The Doctor appears to be traveling solo during his first encounter with the Galyari, suggesting it took place for him post-'Trial'.
Location: The Clutch, in an unknown time period (as Mordecan is human, presumably sometime in Earth's future)
The Bottom Line: 'There's no dagger here, only cloak'
Great races; all credit to Simon A. Forward for giving such attention to detail without slowing down the pace of the story for the most part. On the other hand, with modulated voices and changes, the story's audio medium is sometimes frustrated and creates extra work for the listener. Some great ideas are at work here, but how much more shocking would it have been to have the Doctor apparently 'evil' while in a less controversial incarnation? Despite this, it's a rather entertaining bedtime story.