Guilt
River sat scribbling in her diary as she listened to the rain outside the Storm Cage. The soft whirring of the TARDIS filled the air and a little smile tugged at the corners of her mouth. She looked up as it materialised in the corner of her cell. The smile however, slipped from her face as the Doctor looked up at her from the doorway, a long graze cutting down one of his perfect cheek bones, his hair ruffled and out of place, little singe marks littering his clothing.
"I couldn't do it," he said heavily. "I couldn't save them." River didn't have to ask what he meant, or who, or what had happened. I didn't matter. All that mattered, was that he needed her, now, to be his wife.
She set down the diary and opened her arms to him and he shirked of his jacket and walked, or rather, limped over to her little prison bed. She wrapped her arms around him and he rested his head on her chest, listening in silence to her soft heartbeat.
They simply lay there in silence, River casually stroking her fingers through his long hair, placing a soft kiss on his forehead every now and then. He lay, listening to her heartbeat, scowling into the darkness, his anger at himself slowly, slowly dissipating, to be replaced with grief, and sorrow.
He shifted in his wife's arms so that he could look up at her, into her soft green eyes, and was filled with a sense of just how much he needed her. She was his point of calm, and stillness, in a moment of chaos and terror; the excitement and spark in an adventure. She was his rock when he needed her strength, and he, hers, always.