Erdoğan Bey retires in November after thirty-one years, and the plant has been preparing for it since March. The preparation has taken the form of documentation. He has been asked to write down what he knows, and he has cooperated fully, producing eighty-four pages of procedures for the maintenance of machinery that in several cases is no longer manufactured anywhere. The documents are good. They are also, the engineering manager admits privately, not the thing that is being lost. What is being lost is a category of knowledge that resists the format it is being asked to take. Erdoğan Bey can tell from the sound of the second press whether it will fail within the month. He does not know how he knows this. Asked to write it down, he wrote: "Listen to the machine." The sentence is accurate and completely useless to his successor. The literature calls this tacit knowledge, and the term is now sixty years old, but its practical implications are still routinely underestimated by organisations that believe a process can be captured in a document if the document is long enough. There is a serious argument that the failure is not one of effort but of category. Explicit knowledge can be written because it was assembled from propositions in the first place. Tacit knowledge was assembled from ten thousand corrected errors, and the corrections were never verbal. Demanding its transcription is like asking a swimmer to hand over their balance. The plant, to its credit, worked this out in July and changed the plan. The new arrangement is that his successor, a woman of twenty-nine with better formal qualifications than he has ever held, follows him for the final four months and does the work while he watches. She is not being taught the eighty-four pages. She is being allowed to be wrong in his presence, repeatedly, at a cost the company has agreed to absorb. This is expensive and it is also the only method with any evidence behind it. What remains unresolved is the timing. Four months was chosen because it was administratively convenient, not because anybody believes it is sufficient, and nobody in the building can say what the right number would be. Erdoğan Bey, asked directly, said it took him eleven years. He was not being difficult. He was answering the question.