What the thief didn't find in the safe? (6,5)
I believe the answer is:
danger money
'safe?' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see an association between them that I don't see?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for danger money that I've seen before include "Bonus payment for perilous work" , "Extra pay for risky job" , "Payment for taking risks" , "Extra pay for risk-taker" , "Compensation for those at risk" .)