The hospital came under most pressure during the German advance on the Aisne in May 1918. Courtauld was working in a unit at Villers-Cotterêts, continuing to conduct operations on the wounded day and night in the face of German bombardment and described the situation in a letter to her father: "there came an order for the hospital to evacuate ... Then came an order that heaps of terribly wounded were expected, and we could stay on. We were glad. It seemed horrid to be told to go and leave things behind us. All the night we were hard at it and working under difficulties. Terrible cases came in. Between 1030 and 330 or 4 AM we had to amputate six thighs and one leg, mostly by the light of bits of candle, held by the orderlies, and as for me giving the anaesthetic, I did it more or less in the dark at my end of the patient ... Air raids were over us nearly all night"