Tubman is a technician, and not especially qualified on paper to explain the inner workings of the interrogation suite, but he has a gift for clarity that Neith has found helpful more than once before, most notably in a case where a man was so traumatised by events that the record taken from his mind was compromised. He is what used to be called an oily rag, and is known these days as a high viz in reference to the reflective clothing worn by workmen: a man who climbs in and out of muddy holes to fix things his supervisors imagine are beyond his proper understanding, but which, on a given level, he knows far more intimately and usefully than they do. Tubman doesn’t actually spend much time in ducts, but he does occasionally get down on his knees and rummage under vastly expensive consoles for loose wires, replace circuits chewed by mice, and critique improper neurosurgical interventions with the long experience of a man who will have to fix this mess. At the far end of things, his proper job is dealing with the knackered outputs of complex machinery behaving badly. In a quiet tradition of digital autodidacty, he has no high qualifications of his own, but contributes to the final examination questions of qualifying technicians and medical staff.