There is a moment, just past midnight, when the cooling fans inside the lab on the third floor begin to hum in chorus. Engineers call it the choir. The choir means the model is learning.

Over six months, this magazine spoke with 47 researchers across nine institutions to understand what, exactly, the choir is singing about — and whether anyone is still in the room to listen.

What emerged is not a story about a technology. It is a story about a question we have agreed, quietly, to stop asking out loud: what do we owe a system that may, one day soon, owe us nothing back?

Helena Whitfield is a contributing writer at Luminary Wire.