Beckett can't take her eyes off Castle.

She sits across the table from him and watches as he jokes with Martha while she cleans up their dinner dishes. He could have died today, Beckett thinks for the hundredth time, and then she can see the smoke and feel the dust coating her lungs all over again. She can't even begin to imagine what would have happened if she had picked through the rubble of the building and identified Castle's mangled-

"You're staring."

The interruption startles her. "What?"

"You're staring. At me." The corners of Castle's mouth quirk upward on the last two words.

Beckett suddenly becomes incredibly aware of the clink and clatter of dishes as Martha loads them into the dishwasher. "Yeah, well..." she trails off and shifts uncomfortably on her chair. In the kitchen, Martha continues knocking dishes against one another noisily.

"So," Beckett folds her hands together and blurts out the first subject that comes to mind, "you know Morse Code."

Castle's brows furrow as he thinks, leaning forward and snatching up his wineglass. His smile of realization is lost in his drink. "Course I know Morse Code," he murmurs.

"Research?" Beckett runs her finger along the lip of her glass and watches as Castle swallows his wine.

"Nope." He catches her staring again, and the corners of his eyes crinkle as he grins at her.

"No?"

"Just in case," he says, setting his glass back down and softly tapping his fingers against the table.

"Just in case what, Castle?"

He shrugs. "I don't know, anything."

Beckett stops and stares back at him for a long moment. There's an ache starting in her chest that has nothing to do with stitches and healing tissue. "I don't think you'll ever stop surprising me."

"Darling, I raised him and he still manages to surprise me." Martha's voice drifts over from somewhere near the kitchen sink.

Castle rolls his eyes jokingly and pulls a face that makes Beckett choke on her wine. "Mother don't you have to be somewhere?"

Martha huffs loudly, but begins exiting the apartment nonetheless. "It was very nice to have you over, dear," she says with a wave to Beckett. "Richard should really bring you home more often."

As the door clicks shut, Castle launches into a spontaneous coughing fit. Beckett smiles at him and pushes her chair away from the table. "I should really be going too."

Castle stops coughing and looks at her seriously. "You could stay."

Beckett's stomach drops, and she's sure that her face reflects that feeling because Castle quickly continues.

"I mean, you've, um, you've obviously had some drinks, and I just really don't want you to end up in an alley somewhere asleep with a hobo because you can't remember where you live. So, um, you can stay here, if you want."

Beckett smiles, and it's almost as blinding as the one she gave him in the bank when they were surrounded by strangers and wreckage and subtext. "Do you say that to all the women you bring home?"

"Only the ones I really like," Castle says, and his voice sounds like tell me you need me, always, and I love you all rolled into one.

Beckett half nods, and tries to ignore the warmth that settles itself high in her chest. "OK, Castle, I'll stay."

Always.