I was belaying my climbing partner. It had just rained, we gave a short time for it to dry but the rock was still quite damp. The route was tricky, limited protection placements and few/ no solid holds. Having followed the crack and placing protection, my partner attempted a difficult move and fell. The gear did not hold and he fell 10 metres off the slab, then a further 5 metres down the rocky/muddy/brambly path. I ran to him, slipping on the mud and hitting my chin hard on a rock. Other climbers came to our aid and called emergency services. My partner was conscious though shocked and dazed. Thankfully, he was a bit battered with some cuts but nothing major. Ambulances and an air ambulance attended. The air ambulance was not needed and he was taken to A&E. I drove to A&E. We were very lucky.