The Worldroot Artery follows Ilae, Saevir, and Caer as they travel from wounded Saelithar to Elyndar, where forests are swallowing roads, villages, and rivers. There they meet Mereth, a local healer who realizes the jungle is not invading it is struggling to move through ancient pathways damaged by the Architects. Beneath Elyndar Prime, the group discovers that life's natural cycle has been broken: Growth has overwhelmed the land, Decay has been sealed away, and Renewal can no longer begin. To awaken the Seed of Vaelorin, they must restore balance rather than impose control. Their success allows the Worldroot Titan Sylthara to move without destroying the region and reveals a devastating truth: the Architects did not create the Titans. They discovered a living plantary system and nearly destroyed it by trying to make it obey.