"It would be so much easier if I could ESP it to you," Star said doubtfully.
"Well, pretend I'm a Stupid and tell me in words."
"You remember the Moebius Strip?" she asked very slowly and carefully, starting with the first and most basic point in almost the way one explains to an ordinary child.
Yes, I remembered it. And I remembered how long ago it was that she had discovered it. Over a year, and her busy, brilliant mind had been exploring its possibilities ever since. And I thought she had forgotten it!
"That's where you join the ends of a strip of paper together with a half twist to make one surface," she went on, as though jogging my undependable, slow memory.
"Yes," I answered. "We all know the Moebius Strip."
Jim looked startled. I had never told him about the incident.
"Next you take a sheet and you give it a half twist and join the edge to itself all over to make a funny kind of holder."
"Klein's Bottle," Jim supplied.