Arthur and Pip, two young library apprentices, are tasked with archiving manifests. Arthur discovers an ancient map showing a network of sound conduits beneath the library marked with the same symbol found on the failing structural anchor. They deduce that this ancient acoustic network might be amplifying the town’s resonance problem. Pip remembers the highly specialized, sound-dampening Tannery linen used previously. They realize the library’s own deep storage might hold large banners made from this material, which could act as a massive buffer for the sound node. The episode concludes with them heading into the cold, silent sub-basement of the library to search for the necessary dampening material, hoping to interrupt the acoustic feedback loop before the lighting ceremony.