User blog comment:Garr9988/Episode Ideas/@comment-5782071-20170426023206/@comment-24588058-20170426024119

It's possible that this is the "heart" of the Warehouse, which gives it life. We could separate that from the Tree of Idun. In essence, the orb is the Warehouse's heart, while the Tree of Idun is like it's soul. Something along those lines.

While the Tree of Idun connects the soul of the Warehouse to that of its Caretaker, the heart of the Warehouse is what keeps it going. If a Warehouse were to reactivate, as Warehouse 2 did, then in essence you have two hearts which are vying for control of the Warehouse. Each Warehouse is essentially reborn when they are moved, and without a proper deactivation, the heart is still there; it might not be pumping hard, but it has a pulse. With two hearts, only one can survive, though how that might get decided if for some reason one could not deactivate the previous Warehouse is unclear.

On the other hand, it seems strange to me that putting a key into a constellation would calm down a Warehouse's heart. But perhaps there's some sort of logic to it, which I can't explain; it's also possible that this is the Warehouse's soul in its early form, before the Tree of Idun arrived, and that once the Tree arrived, it acts as both the heart and soul of the Warehouse, removing the need for the orb to be visible. We've never seen the Tree of Idun, so it's possible as well that this orb lies in the chamber along with the Tree.