| stickler(difficulty, question, secret, puzzle, obscurity) |
| stumper(difficulty, question, secret, puzzle, perplexity) |
| subtlety(difficulty, question, secret, puzzle, obscurity) |
| teaser(difficulty, question, secret, puzzle, perplexity) |
| thriller(difficulty, question, secret, puzzle, subtlety) |
| twister(difficulty, question, secret, puzzle, obscurity) |
| bewitchment(perplexity, abstruseness, inscrutableness) |
| confidential information(expression, perplexity, abstruseness, inscrutableness) |
| cruces |
| hocuspocus(perplexity, abstruseness, inscrutableness) |
| magic number(expression, perplexity, abstruseness, inscrutableness) |
| occultism(perplexity, abstruseness, inscrutableness) |
| privileged information(expression, perplexity, abstruseness, inscrutableness) |
| puzzler(difficulty, question, puzzle, perplexity, mystery) |
| riddles |
| runes(perplexity, abstruseness, inscrutableness) |
| skeleton in cupboard(expression, idiom, perplexity, abstruseness, inscrutableness) |
| voodooism(perplexity, abstruseness, inscrutableness) |
| witchcraft(perplexity, abstruseness, inscrutableness) |
| witchery(perplexity, abstruseness, inscrutableness) |