If we're being honest, up until this point I've been avoiding both this prompt and the World War I era of the show, so I figured why not tackle them both at once! I definitely wish we could've seen a moment like this on the show, so I hope you enjoy :-)

She wasn't asleep when Robert crept into the room, although she should have been. It had been nearly two hours since O'Brien took her dinner tray away and helped her to lie down, settling a hot water bottle against her spine to ease the aches that lingered from her fall and its aftermath. Her body was exhausted and sore from the small amount of effort the garden party had taken from her, but her mind simply wouldn't rest. How could it, when the afternoon had dealt them such a blow? War. The word was practically branded on the backs of her eyelids, assaulting her every time she closed her eyes, and so she opted to stare at the ceiling in the dark until Robert joined her, hoping his steady presence might soothe her into sleep.

Now he was here, slipping gingerly into bed beside her, clearly thinking she was asleep and trying not to jostle her. He settled on his left side, but she spoke before he could get too comfortable.

"Robert?" she croaked, her voice still so weak. "Can you turn on the light?"

He did as she asked before rolling to face her. "I'm sorry darling, did I wake you?"

"No, I can't seem to sleep." Pushing herself up slightly, she leaned back against the headboard. He nodded, not needing to ask what was on her mind. Instead he reached for her, stroking her brow. She turned her head into his touch and felt some of the tension seep from her body.

"What happens now?" she asked after a moment.

"They'll want to get men to the front as soon as possible. Matthew will enlist, of course, he told me after dinner. We'll lose some of the servants as well. Carson says Thomas already has a position waiting in Richmond and I suspect William will go before long."

He was intentionally avoiding the most important part of her question, and although the answer terrified her she had to hear it. "What about you?"

"I don't think they'll send for me right away, not when there are so many younger men eager to fight."

"But…" she prompted.

"I expect I'll have to go eventually."

"You can't." She didn't care how childish her words sounded: they were true. He couldn't leave her. They had only just lost their baby; how could she be expected to lose him too?

"Cora," he said her name calmly, making her feel more like a petulant child than she already did. "I'm the Lord-lieutenant, they won't let me stay back and do nothing."

Hot anger flared in her chest at his words and she jerked her head away from his hand. "Taking care of your family is not nothing."

"That's not what I meant." Robert let his rejected hand drop to her shoulder, kneading the tense muscles there. His face seemed suddenly pale and drawn in the lamplight, and for the first time Cora realized that perhaps he was just as tired as she was.

"I know," she sighed, her anger fading as quickly as it had come. She shook her head, unsure of exactly what she meant to say. "I know, I'm sorry. I just - I'm frightened."

"So am I," he replied earnestly.

Somehow his admission of fear comforted her. In the morning they would have to be Lord and Lady Grantham, putting on a brave, united front for the rest of the world. But for tonight, in the soft vulnerability of their marriage bed, they could be Robert and Cora, clinging tightly to one another as they took the same blind leap into whatever the future held for them.

"Promise me," she said seriously, holding his gaze with a fierce intensity, "promise me that we'll be alright - all of us."

"Cora, I -"

She cut him off, not wanting to hear the end of his statement. "I know. But please promise me, just for tonight."

She had asked Robert to make a similar promise once before, nearly fifteen years ago when he left to fight in the Boer War. She had been a young mother then, facing the very real possibility of raising three small daughters alone. Her fear was not any less now that their daughters were grown; it was perhaps made even greater by the memory of what it felt like to have her husband gone for months at a time, always wondering if or when he would come home. Though it was an admittedly empty promise, she would need it to carry her through the long, lonely nights should he be called upon to serve again.

Robert must've had the same thought, for he nodded, his hand making a soothing pass down her arm. "I promise."

It was enough to satisfy her for now. She slid down the headboard a bit, unable to suppress a yawn. "You need to rest," Robert said as he reached to extinguish the lamp, bathing the room in darkness. "It's been a long day."

"Will you hold me?" she asked when he rolled onto his back beside her.

He hesitated. "I don't want to hurt you."

"You won't."

Accepting her assurance, he carefully eased her into his arms, mindful of places where dark bruises still mottled the skin beneath her nightgown. She whimpered quietly despite his gentleness, but he tenderly shushed her, and she relaxed. The hot water bottle was replaced with a warm hand rubbing her back. He kissed her hair as she nuzzled into his side.

If she squinted, she could almost pretend as if this were any other night, as if they were not grieving a terrible loss, as if the entire world was not dangling from an incomprehensible precipice. She allowed herself the sweet luxury of denial, sliding a hand across his chest, her fingers moving to play with the collar of his nightshirt.

"I love you," Robert said into the darkness, his voice rumbling against her cheek.

Cora had heard those words from with increasing frequency in the days since her miscarriage, and they gave her as much comfort as any touch or caress. "I love you too," she murmured, her eyes closing involuntarily. It really had been such a long day and she couldn't fight the exhaustion any longer, nor did she need to. She was safe with Robert - in his embrace, his love, his promise - if only for tonight.