It was February 2024 when Noland Arbaugh, the first person to get Elon Musk’s experimental brain chip, rolled across the stage in a wheelchair during a Neuralink “all hands” meeting, revealing his identity for the first time. The room, filled with Neuralink employees, erupted in applause as Arbaugh—who dislocated two of his vertebrae in a swimming accident in 2016 and has since lost sensation and movement below his shoulders—smiled ear to ear in his chair, a red Texas A&M hat planted on his head...