The Chronos key was shown in the final video on the Book of Briars website after the Book was restored.
Each of the images unlocked at the end of each phase included a series of roman numerals. Using this, the Mountaineers were able to translate them to a series of numbers.
Deirdre came back to the forums, revealing that she had visited Orvin Wallace. There, she found the true ending to The Monarch Papers on Orvin’s shelf. Sullivan had told Orvin to burn it, but he couldn’t bear to follow his request. The book was Sullivan’s journal, and it was a record of Sullivan’s life and what he knew of magiq. The Storm had wanted to take Sullivan away in exchange for another magimystic artifact, so in order to ensure that Sullivan’s plan to open the Book of Briars succeeded, Sullivan allowed himself to be taken. He began living in Neithernor, both to hide from the Storm and to use the slowed time difference to live long enough to see his plan succeed. However, this meant that Sullivan had become Neithernorian, and returning to the mundane world would kill him. Sullivan was not dead, but he could only return in glimpses, leaving the door to Neithernor open. Orvin also told Deirdre about her walking stick – that the magiq she used was not from the mundane world, so the stress was slowly breaking it. This led Deirdre to realize that, like the stick, she was not meant for this world.
Deirdre decided to go to Neithernor herself, with Cole agreeing to join her. She wanted to find her father and return his walking stick to him. Before leaving, she gave one last hint to the Mountaineers: “The foreword was all you’d need to open the book.”
"For my dearest girl.
This was your favorite story the last time I saw you.You would have me read it to you every night before bed. Do you remember?
Memory, after all, is a very funny friend.
Sometimes he loses the fondest of thoughts and sometimes the saddest he holds onto forever. I hope that he has kept for you more fond memories than not, and I hope that I am somewhere with you, in a memory held tight.
The way things are can’t be undone, only perhaps rewritten someday. The corvids have come and gone. It’s time to leave the glade.
For now, I go to a place where you can’t.
But I am always your caterpillow, and you are my ant."
Adding in the foreword, Mounties were able to use the numbers to count through various words in The Ant and the Caterpillow. The final result was:
“The Book of the Wild
The Book of Kings
Two worlds rebound
In butterfly wings”
When Mounties put the phrase into the Book of Briars, it led to a new page. The book was finally open.