Mohammed el Khadi guided us to a deserted bit of line just before midnight. I dismounted and fingered its thrilling rails for the first time during the war. Then, in an hour’s busy work, we laid the mine, which was a trigger action to fire into twenty pounds of blasting gelatine when the weight of the locomotive overhead deflected the metals. Afterwards we posted the machine-gunners in a little bush-screened watercourse, four hundred yards from and fully commanding the spot where we hoped the train would be derailed. They were to hide there; while we went on to cut the telegraph, that isolation might persuade Aba el Naam to send their train for reinforcements, as our main attack developed.