A suspicious package arrived at Scotland Yard containing a sealed glass jar filled with liquid water and a live goldfish. Attached was a note: 'I will flood the city archives at noon.' The bomb squad evacuated the room, but Detective Miller laughed and told them to unpack it. Why was there no danger?
A goldfish cannot survive in a sealed jar without oxygen for long, meaning the package was mailed days ago or was completely harmless.
A sealed jar containing a live fish has a strictly limited oxygen supply. If it was meant to be an immediate threat, the fish would already be dead, or the jar was simply a bizarre riddle with no explosive components.
About this riddle
Detective riddles are tiny mysteries. Look for the detail in the story that does not fit; it is usually the clue that solves the case.
Difficulty: Hard. More like this: Detective riddles with answers or try Truth & Lie Island for a different kind of puzzle.
More detective riddles
During a summer heatwave, a jeweler was found unconscious behind his counter. The front door was locked from the inside, and the air conditioning was blasting ice-cold air. On the floor lay a pool of melted ice water near a shattered lightbulb. The detective smiled and said, 'An inside job.' What gave the thief away?
A suspicious package arrived at a precinct addressed to Inspector Reed. Inside was a ticking clock and a note written in cut-out magazine letters: 'YOUR TIME IS UP.' Reed calmly picked it up, threw it in the trash can, and walked away. Why wasn't he worried?
A valuable sculpture was stolen from a pedestal. The security cameras showed the room was empty for ten minutes, then suddenly the sculpture was gone without anyone entering or leaving the frame. How did the thief pull off the heist?
A museum curator was found bound and gagged in the vault. He claimed masked men tied him up and stole the golden chalice. Detective Lane noticed the curator's wristwatch was facing outward on his wrist instead of inward. What did that prove?
A night watchman claimed he fell asleep and woke up to find the office safe blown open with dynamite. Investigators found a heavy soot mark on the wall directly above the safe door, but the watchman's face and uniform were completely clean. What did the forensic team deduce?
The victim's watch was found smashed in the hallway, reading 3:45. The coroner established time of death as midnight. Detective Cole knew the killer smashed the watch intentionally to mislead investigators, but what specific detail about the watch's internal gears proved it was stopped manually hours before midnight?