Spy Pigeon is a common secret card belonging to the Janus branch. It is Card 87.
Description[]
"Pigeons have been used as messengers and spies for centuries. During World War I, the birds were fitted with cameras so they could take photos beyond enemy lines. A pigeon named Cher Ami was even awarded the French Croix de Guerre (Cross of War) for heroic service! Despite their bravery, spy pigeons prefer peacetime missions. Perhaps that's why a few have been spotted flying over Neuschwanstein Castle in Bavaria, Germany. Who sent these birds and what are they looking for? Collect all cards in this combination to unlock a Clue!"
Clue[]
This card, combined with Card 84, Card 103, and Card 104, forms the Clue Pearl.
The Black Book of Buried Secrets[]
In this book it is explained Janus would often use pigeons to take pictures of enemy HQ's.