interspace n.

You are in what is called the inter-space dimension—which is a dimension—a sub-dimension, if you will—lying between your own world—the world which you just left—and Saranoff’s world. This inter-space dimension is what you in your world call the Fourth Dimension.

‘The laws of the five-dimensional inter-space,’ explained the Engineer, ‘are not the laws of our four-dimensional universe.’ [Ibid. 73/1] They can break through the time-space curve…and they can travel in the fifth-dimensional inter-space.

The strain of watching, of staring into the electric curtain that opened into some dimensional interspace, tore at my eyeballs.

They are still in the inter[-]space between our three-dimensional worlds. [Ibid. 25/2] Only living creatures can find their way through the interspace. And as they pass through, the laws of the universe change.

The ship materialized out of interspace and dropped him on Verna, the single planet of a Sol-type sun.

You postulated the essentially two-dimensional nature of time itself, and the consequent existence of interspace.

As one envelope unwinds, the purusha hovers in inter[-]space until another issues for it to inform. But that time of hovering is out of the seven-dimensional time stream.

You don’t expect me to get us into interspace from the disc surface?… We wouldn’t have a chance!

I didn’t know interspace was haunted, unless you programmed a scary experience. [Ibid. 104] Interspace lets people let off steam without hurting anything in the real world. The whole point is that you can do anything you want.