Related Clues:
- Exhibitionist's problem
- Hard puzzle
- Difficult problem unravelling ropes
- 'The Imitation Game' machine
- Puzzle formulated in game
- Baffling mystery
- Tangled ropes can present a problem
- Imagine missing one cracking puzzle
- Hard one
- Puzzle in game worked out
- After midnight drink and drug, turned to puzzle
- Puzzle's new meaning missing at core
- Nazi cipher machine broken by the Allies
- 'Why is a raven like a writing-desk?,' e.g
- Brain twister