Two types of nodes are present in Chasing Shadows, Ensnaring and Summoning. Both are story-related structures that appear alongside sockets on fields where the Forgotten was previously sealed and summoned. Most of them are ruined (presumably by the Forgotten's previous actions) and instead of ensnaring or summoning, they charge and deal damage to randomly targeted nearby monsters whenever any monsters are either frozen or cursed.
Ensnaring nodes build up charge whenever monsters within range of them are frozen. On field X5, Ensnaring Nodes appear in fresh condition along with a fresh Gem of Eternity Socket. The nodes then require nearby enemies to be frozen so they may charge up and, upon reaching full charge, activate the socket in hopes of sealing The Forgotten again.
Summoning Nodes appear in fields P1 and V2. These are charged when nearby monsters are cursed instead. It is through these nodes that The Forgotten appeared in the first place.