A secret defense prototype valued at $50 million went missing during a four-step courier journey across the city. Each courier used a digital receipt to confirm they passed the package along. However, the package never made it to its final stop.
Route and Timing Information:
- Courier A (Sarah): Traveled from the Central Hub to the Museum District between 11:00 and 11:45 AM.
- Courier B (Marcus): Carried it from the Museum District to the Financial Quarter from 12:00 to 12:30 PM.
- Courier C (Elena): Moved it from the Financial Quarter to the Industrial Zone from 1:00 to 1:45 PM.
- Courier D (Jake): Took it to the Secure Facility from the Industrial Zone between 2:15 and 3:00 PM.
Individual Accounts:
Sarah: “I handed over the titanium briefcase to Marcus right on the museum steps at 11:43 in the morning. He had on the usual blue courier outfit and showed me the right ID. I need to confess that the digital lock on the briefcase was blinking green because I had tried to open it, but couldn’t figure out the code. Marcus looked like he knew his job, signed the tablet right away, and didn’t take much time.”
Marcus: “I got the briefcase from Sarah and went straight to the Financial Quarter. , I didn’t notice the lights on it when she gave it to me—I was rushing. Traffic on Fifth Street slowed me down, took me 35 minutes when it should’ve been 30. At 12:35 PM, I handed it to Elena at the bank plaza, and the green lock light was blinking at that time. Elena was on her phone when I got there. The briefcase felt heavier than what I’d expect for this kind of delivery.”
Elena: “Marcus showed up 5 minutes late, but I grabbed the briefcase by 12:35. When Marcus handed it to me, I saw a red light on the digital lock flashing every 5 seconds. By 1:42 PM, I passed it off to Jake at the loading dock in the industrial area. Jake got there and was already waiting with his van doors open.”
Jake: “I picked up the briefcase from Elena at 1:42 PM. When I got it, the digital lock had a red light that blinked every 5 seconds. I headed straight to the facility, but I got delayed for half an hour because of a chemical spill cleanup on Industrial Boulevard and the rainfall. By the time I made it there at 2:55 PM, I found the briefcase was empty.”
Extra Evidence:
- GPS logs confirm all couriers stayed on their assigned routes.
- Security footage verifies every handoff happened when it was supposed to.
- Experts found traces of moisture and dirt inside the empty briefcase.
- The digital lock maker states: Green means secure. Red means briefcase has been opened. A blinking green light indicates tampered or unsuccessful access attempts.
- Every courier’s tablet recorded their location in 5-minute intervals during their shift.
The Mystery: Who took the contents of the case, and what undeniable evidence proves it? Keep the timing of events, lock behaviors, and the rainstorm period from 12:45 to 2:30 PM in mind while solving this.
View the answer
Solution:
Elena is the guilty courier.
Key evidence: Elena says Marcus gave her the briefcase with “a red light pulsing every 5 seconds,” but Marcus explains he passed it on as Sarah gave it to him. Sarah’s tampering caused blinking lights, but not the red alert Elena described. The decisive clue involves the moisture inside the briefcase. A heavy rainstorm happened from 12:45 to 2:30 PM, which lines up with the time Elena had the briefcase in her possession from 12:35 to 1:42 PM.
The dishonesty: Elena gave false information about the light color to make others believe the briefcase was already in an alarmed state when it was handed to her. During the rainstorm between 12:35 -1:42 PM, she opened the briefcase (which explains why it was damp inside), took the items from it, and later said it was already tampered with to avoid blame.
Proof backing this claim:
- Sarah says she tried to mess with it but failed, which led the lights to blink at first.
- Marcus explains the lights were just “blinking” and not in full red alert mode.
- The water inside shows someone opened the briefcase while it rained between 12:45 and 2:30 PM and not before that. Elena was in charge of it then.
- Elena’s story about “red pulsing lights” doesn’t match what Marcus said, which makes it seem like she’s trying to claim the briefcase was already opened when she received.
- Jack also stated that the red lights were already on when he received the briefcase confirming to Elena’s story that it was already opened when handed over to him.
Elena used the rainstorm as a chance to open the briefcase in a hidden spot. She emptied it, allowed rain to seep into it, and then made up a story about seeing red alert lights. This was to make it appear as if the tampering had happened before she had it.