Related Clues:

• Crossword frame
• Fingerprints, e.g.
• Holmes quest
• Criminal game?
• Graph-paper pattern
• Power system
• Sleuth's aid
• Sleuthing aid
• Power network
• Footprint or loose thread, perhaps
• Map aid
• Crossword diagram, e.g.
• Miss Scarlet's game
• Detective's quest
• Part of a control tower screen