In order to enter, one must receive a pass from the administration bureau of the Silver Linked Towers. Another way was to prove that you were a researcher belonging to the Silver Towers by presenting a silver key. The last pass was for the Elders of the Silver Linked Towers. They had tower master keys which were engraved with nine canes.
Because this gate existed, there was no need to post people to watch the front of the tower. And Mira of course possessed one such tower master key.
When Mira advanced in front of the gate like she has always done, she noticed something unusual.
Up until now, the gate was like an automatic door. By approaching the gates it would open, but right now the gate did not how any response. Mira who tried to advance the same as before moved back in a panic after she had almost collided with the gate.