Derek nodded, still in motion around the room, Mark cradled against his chest, one large hand spanning the back of his head and neck. "Gloria hurt her back," he said softly, interrupting his humming to explain, though his voice was light, slightly higher than his usual speaking voice. "She asked for Miranda to come help her in the kitchen." His eyebrow quirked upwards, an acknowledgment that she was essentially unsuitable for replacing Miranda, or Gloria.