Walsingham

Finally, out popped a telltale name: Walsingham, Queen Elizabeth’s infamous spymaster.

One of Elizabeth’s spies, Sir Francis Walsingham, tricked Mary into believing her letters were secure and intercepted one supporting Elizabeth’s assassination.

But seven of them had been intercepted and decoded by Walsingham’s network, so deciphered copies were in the U.K.’s National Archives.

After deciphering that the woman writing the messages had a son, the team spotted several mentions of “ma liberté,” as well as the name “Walsingham.”

She also expressed her deep anguish over her separation from her son, James, made king of Scotland at age 1 by her forced abdication, as well as her mistrust of Elizabeth’s spymaster, Sir Francis Walsingham.