The Old Improbable Island Wiki

This peculiar dimension was formerly inhabited by Kassil before Cheshire Cat decided to wander in; the sudden presence of another lifeform in the pantemporal dimensional matrix caused it to collapse, expelling both present within it; CC was unharmed, not being a natural resident, while Kassil's many potential selves were expelled randomly across all the timelines he existed in. The one who ended up on the Island was a somewhat confused engineering of steam and clockwork, capable of creating clockwork creatures that assumed a life in and of themselves.¹⁾

In theory, four-space still exists at the Planck Scale, but it is effectively out of the reach of even the wildest Mad Science or Improbable Effect.²⁾³⁾