The scene
Bookbinding Workshop · Assembly tableFour envelopes travel on a tray. One contains a stamp showing a crown; the others contain paper samples. The envelope with the stamp ends up empty.
Two recorded moves took place before the envelopes were handed out. Follow the valuable envelope to its final recipient.
What we know for certain
One worker removed the crown stamp from the envelope they received. The envelopes stayed closed during the moves. Nobody exchanged positions after they were handed out. The second position went straight into a sealed automatic compartment and could not be opened by a person.
The three accounts
Ada Bosch
Gluing«I received position one. It contained only sample paper.»
Bruno Casal
Inspection«I got the third position, but I did not remove any stamp.»
Clara Vidal
Pressing«I worked with the last envelope in the row.»
Examine the evidence
0 of 5 openedOpening these five clues does not cost points.
01The original row
Before anything moved, the crown stamp was in the envelope at position two. Positions are numbered from left to right: one, two, three and four.
02The first move
Only the envelopes in positions one and four were swapped. The envelopes in positions two and three were not touched.
03The second move
Then the whole row was reversed: one moved to four, two to three, three to two and four to one.
04The final handover
Ada received position one; Bruno, three; and Clara, four. Position two went into the closed automatic compartment.
05The empty envelope
The manufacturing mark confirms that the envelope recovered empty is the one that held the crown stamp before both moves.