She wakes up shaking and sweating through the thin Tshirt she wears to bed. Sometimes she screams, sometimes she gasps for air, but there are always tears.
Draco knows that she is beyond reason when she wakes up like this. He doesn't say anything, doesn't try to make her understand that her nightmares are just that, nightmares. He knows all too well what it's like to be haunted by your past. He simply holds Hermione close as she shakes, letting her tears drench his shirt as he holds her to him, rocking her back and forth slowly.
Some nights it takes longer than others, and she can't lay still in their bed, instead she gets up to pace the room, her hands tangled in her hair. She then traces the words on her arm slowly, as though she can still feel the slow burn of the enchanted knife on her skin.
At that point Draco intervenes, dragging her hands from her body and laying her back down onto their bed as he holds her to him tightly.
Sometimes, it's not just her tears that stain his shirt.