- Mack always moves in straight lines, turns at right angles.
- Zag moves in a helpless way at first, but can develop later.
- You may have met Mack and Zag aboard the 64.
In a dream, Mack said to Zag: "We can't hug but we can kiss. Please lend me your cat for I haven't taken my pills!"
What are the real identities of Mack and Zag?