Doctor Who Series 12: 10 Huge Questions After Spyfall Part 2

10. What Were The Kasaavin Doing On Earth?

Like the Silence before them, if we are to believe the Master, then the Kasaavin have been hidden on Earth for centuries, acting as spies. Their original motive was one of self-defence, protecting their own realm from discovery and invasion. Humanity is one civilisation among many they are keeping tabs on.

We know very little about them other than their role as alien spies. Are they paranoid by nature, or do they have cause to be wary of every other intelligent life form outside their reality? Why do they want to stay hidden? Do they have anything besides themselves to protect?

Their reality, some kind of giant organic data-centre, might look like an eternal maze of thick weed-like protrusions, but it is finite. The Master tempts them with his plan for human hard-drives, reasoning that they could do with the additional storage space.

There are too many unknowns for these creatures not to be making a reappearance, but a degree of mystery ought to remain even if we do find out more about their civilisation. The most effective aspect of the Kasaavin is their ghostlike and uncanny forms. They are intrinsically unknowable and are all the better for it. Going forward, they might prove useful allies for the Doctor, especially if they hold valuable intel on the Time Lords. Could they have been part of how the Master uncovered the ‘truth’ about the Timeless Child?