Ted reaches out to grab his laptop, planning to just sit here right next to her, sitting so he can easily notice her moving even while looking at his screen.

He realizes Sherlock's still standing there, and looks up at him curiously, before he realizes why, from the way he's looking at Joan. "It's alright, I'll look after her. Promise," he says softly.

"Hey, could you maybe make me a coffee before you go to bed?" he asks as an afterthought, because that would definitely help him stay awake. And it'll give Sherlock a purpose for leaving the room that perhaps feels more productive than just the need for sleep.