Cassian had learned about the library from Mig and it had become an alternate meeting place. There were good sight lines when you knew where to look and Cassian appreciated the shadows.

He wanted to see who the Rebellion had sent and then get Mig and the others off safely. Near one of the round windows, he saw a Twi'lek and shifted to get a better look, nodding slightly to himself as he recognized Hera and Kanan beside her.