The Throttle

The throttle is the central apparatus the scholar Theodora built deep within the Vex Caves, seated in a fitting she called its cradle. The party reached it at last: a ring of dark metal, about the width of a dinner plate, etched with concentric channels, resting on a raised pedestal in the caves' great workshop. It is plainly kin to the clay apprentice-disc found earlier in the lab, only far finer, and an attuned instrument reacts to it more strongly than to anything else in the caves.

By her account, the throttle regulates the flow of the concentrated weave that pools in the caves, channeling it in a steady, controlled line that made the rest of her instruments and studies possible. It was the achievement of her fourth year there, and its working left her trembling.

Her writings return again and again to a single warning: the throttle must never be removed from its cradle. She held that the caves were dangerous before her and would be dangerous after her, and that her whole life's work was not worth what would happen there if the throttle were taken. Her final entry pleads with whoever finds it: "do not move the throttle."

Taken From Its Cradle

The workshop holds one more secret about it. A sealed brass door with no handle stands in the same room, its face etched "Conduit heart. Remove the throttle and proceed. Be wary of the tide." — so lifting the throttle from its cradle is the only way to open whatever lies beyond it. The party at first left it where it sat, weighing that against Theodora's warning; a rival crew of relic hunters had also come into the caves seeking it. In the end, after driving that crew off, the party lifted the throttle from its cradle and carried it out. It is now in their keeping.

Removing it did two things at once, just as Theodora's writings had implied it would. The sealed brass door ground open, and the tide surged in faster and higher — turning the last stretch of the escape into a race against the rising water.

What the Throttle Does

Beyond the opened door lay a further chamber whose walls were lined with brass conduits, all converging on a pedestal — a room Theodora had built to study the weave. Seated into that pedestal in a particular orientation, the throttle made the ambient weave visible to the naked eye: a shimmering geometric lattice of arcane energy that filled the chamber, plain to the whole party at once. With the throttle in place the lattice held strong and steady — healthy, but stilled, not drifting in any one direction; lifted away, it vanished entirely. The throttle, then, is a governing piece: seated in its cradle it gathers and steadies the concentrated weave, and removed, it leaves that force to run wild — which is why Theodora begged that it never be moved.