Nathaniel and his crew temporarily leave behind their ship and join a salvage team. Arriving in a thick belt of unstable, magnetic asteroids, they are let off in a gigantic bell-shaped ship damaged beyond repair. When the salvage ship is suddenly destroyed with the captain and half the crew inside, Nathaniel and the other half of the crew must find a way to repair the unrepairable.
The ship’s alien design requires that a living pilot be in control at all times or else the ship begins to move erratically. The pilot controls consist of a pan of fluid that the pilot must stick his hands into so that the machinery can sense his hand movements. The ship moves by projecting a solid surface of highly curved space below it and then rolling across it on wheels. The interior is clearly designed for very large beings and this makes repairs and control difficult, as do the recurrent meteor storms and attacks from a native blob. Able to control its interaction with the electromagnetic force at will, the blob covers itself with stones and uses them to punch, turns invisible, passes through walls, and squashes people.