Maybe it’s just a simple substitution—look for patterns, maybe a book cipher or a reference to a date or a location. If you slide the numbers through a Caesar shift or map them to letters, a phrase might pop up. Check the archive logs for any repeated sequences or anomalies. If it’s a prank, it’s probably a joke about the mayor’s coffee machine. If it’s serious, it could be a hidden ledger entry or a clue to a missing asset. Start with a frequency analysis; that usually reveals the trick.

If the gaps are irregular, line them up on a timeline and see if they line up with maintenance windows or shift changes—those are often the blind spots. Look for a pattern where a long pause is sandwiched between short, regular ticks. That could be the signal the back‑door is triggered. Make a chart, mark the gaps, and see if the numbers correlate with those silent windows. If it’s a real route, the timing will be precise, not random.