The name for a group of Sensates who are bound together and share a group mind. Sensates within a Cluster can not only "visit" each other without making eye contact, but can share memories, emotions, and skills with other members of their Cluster, singly or as a group.
It is not known how a Cluster is created, or how many Clusters can exist at a time. Jonas Malicki described himself and Angel (his lover) as the "father" and "mother" of the current Cluster, but it is not known if he is speaking figuratively or literally. Angel's death seemed to trigger the creation of the current Cluster, but she was not the last member of her Cluster and possibly not the last female member.