What can be learned from a fluid, calligraphic line? The space these lines are allowed to roam is crucial: the field of parallel lines –reminiscent of handwriting paper — demarcates a set of norms, a set of steady limits. But unlike the sheets of paper on which children learn to perfect their penmanship, the very point of the physiologist’s use of his lined paper is to help track when the needle and its ink spill or stagger out of bounds. Here, the normal and the abnormal become dependent on one another, not because they rest on opposite sides of a gradient, but because they are contours that pull away from each other, converge, and, in a split second, intersect.