Geometric polyhedron on the side of the torso

The die turned up in the cold drawer of Mr Arkwright's bench three weeks after the funeral, wrapped in a page of the Hull Daily Mail. Twenty faces, he had written on the paper in pencil, and underneath, smaller: do not roll indoors. I laughed for the first time since March. You always said he was the only man in Yorkshire who could draw a solid without lifting the nib.

I have been trying to finish the work he left me. Thirty edges need inking, and I have done twenty-nine. I go in before the bakery lights come on across the lane, when the street is still blue and Mrs Okafor's ovens are only warming, and I sit at his bench and follow his lines with the pen until my wrist aches. Every corner is a place he decided to stop. Nothing is shaded. He said shading was for people who did not trust their edges.

Enclosed are the die and a sheet with the counts, which I have checked four times. Twenty faces, thirty edges, twelve corners. The last edge is the one that worries me. It runs from the corner nearest the window to the one that catches the morning, and every time I lay the ruler on it, my hand goes steady for no reason I can explain.

Come in June. Bring your good ink and the small brass ruler from your mother. We will draw the thirtieth line together, and then we will roll the die across the floor and see which face the morning chooses.