The Silent Gatherers are a secreted group of people employed by King Taravangian who collect quotes uttered by the dying (death rattles) - who are intentionally being drained of their own blood to produce the effect of the quotes - in a secret hospital beneath his palace.
Taravangian created the hospital and induced the deaths because some of the dying speak cryptic sentences just seconds before their deaths ... sentences in which he found information concerning the True Desolation or Everstorm. So in order to prepare for it, he began collecting the quotations.
It is a large, long room with wide railings on the sides. The room is filled with hundreds of beds.