He'd been catching up on his tech journals, or at least trying to. Mostly he'd been dozing off, because he'd been overworking himself in the few days he'd spent between getting things straightened out with Ianto and going to talk to Jack, and it was catching up with him. The sound of someone knocking at the door woke him up out of the state of half-asleep he'd been in, and he set his long-abandoned journal aside, running a hand through his hair. Right. He should probably go answer that.

Stifling a yawn, he stood, wondering if maybe the captain wanted something, but when he opened the door... "Sulu?" He scrubbed a hand over his face, and stepped back to let the other man in. "Hey. Sorry. I was." He gestured vaguely behind him. "Catchin' up on things."