Disclaimer: The characters belong to Neil Gaiman and Terry Pratchett.

A/N: This is a sequel to a ficlet by snzsnchillz on Tumblr. In that ficlet, Crowley falls ill in the 1700s and Aziraphale accuses him of becoming a vector of illness on purpose, calling him a "plague rat." From then on, Crowley takes to hiding from everyone and especially from Aziraphale whenever he gets sick. But Crowley gets sick right after saving the world, and Aziraphale breaks into his flat to check on him, at which point Aziraphale realizes he was wrong to think Crowley was faking illness and resolves to take care of Crowley. That's where my story picks up.

"You're burning up!" says Aziraphale as he feels Crowley's forehead.

"No shit," Crowley mutters. He can't recall ever feeling this bad without discorporating.

"Oh, my dear," Aziraphale murmurs. "What can I do for you?"

Crowley draws back enough to shoot his angel a bewildered look. "Do for me? You need to leave, Angel. I told you, I don't want you to catch this." Three sentences is apparently past his limit for talking—he sticks his head in his elbow and has a full-blown coughing fit, and somehow Aziraphale stays, rubbing his back and murmuring something Crowley can't quite make out over his own coughs.

When Crowley finally finishes coughing, somewhat surprised that his lungs don't appear to have exited his body, Aziraphale says, "Crowley. The reason I thought demons couldn't get sick is because angels can't get sick, and you were an angel once. So please, don't worry about me. Just tell me, what can I do to make you feel better?"

Crowley pitches forward, sneezing. When he's done, he sniffles and says, "This can't be enjoyable for you. There's no need for you to stay."

Aziraphale's inhale sounds shaky. Crowley looks at him in alarm. Aziraphale's eyes seem to be watery. Was he wrong about illness? Is he holding back a sneeze? Has Crowley infected him already? In a thick voice, Aziraphale says, "Crowley. My dear. Please. I would want to take care of you regardless, but I especially need to after I hurt you so badly. I have so much to make up to you." Oh. It wasn't a sneeze Aziraphale was holding back; it was a sob, which Crowley realizes as it wrenches its way out of Aziraphale and tears Crowley's heart in two.

"Angel, no," says Crowley as Aziraphale starts to cry in earnest. "What could you possibly have to make up to me? You're perfect."

Aziraphale puts his head in his hands and weeps, and Crowley feels helpless. He can't even hold Aziraphale—as if the angel would want that, from him—because he knows he'll need to cover his own coughs and sneezes too frequently for an attempt at holding Aziraphale to be anything other than awkward. He just sits on the bed beside Aziraphale, turning away from Aziraphale whenever he needs to cough or sneeze, trying not to make a nuisance of himself.

It's several minutes before Aziraphale wipes his face with his hands—all the tissues in the vicinity are used—and sits up straight. "Crowley," he says in a broken voice. "I think we've learned rather definitively lately that no one is perfect. And even if perfection did exist, I would not be it. I called you a plague rat. I hurt you. And I didn't realize it for centuries. How could you possibly forgive me?"

"What is there to forgive?" Crowley asks helplessly. "I'm a demon. You only drew the logical conclusion."

"My dear," says Aziraphale, tracing over Crowley's face with tear-sticky fingers. "I know you. I ought to have known you wouldn't do that."

Crowley draws away from Aziraphale for another coughing fit. Aziraphale rubs his back again, and the emotion that stirs up in Crowley tightens his throat and leads to more coughing. Finally, finally, he finishes and slumps forward, spent.

"Please," Aziraphale begs. "How can I help?"

"Tea," Crowley rasps, feeling weak in every sense of the word. He ought to get Aziraphale to leave him and never come back, and yet. "With honey. And tissues. And medicine. I can make you a—a—" He breaks off to sneeze. "I can make you a list if you want to go to the chemist's. But really, Aziraphale, you don't need to trouble yourself for me."

"You would have gone to Alpha Centauri for me," says Aziraphale. He had stood, but now he sinks to his knees in front of Crowley and takes Crowley's hands, and Crowley swallows against the urge to cough. "You risked being discorporated for me. All of this, even after I hurt you. How could I live with myself if I refused to trouble myself for you?"

Somehow the urge to cough transmutes into the urge to cry, and Crowley can't help himself; he pulls his hands from Aziraphale's and uses them to cover his face instead and lets the sobs wrack his body. Aziraphale moves back to the bed to sit next to Crowley and wraps his arms around him, pressing soft kisses to Crowley's temple. It's too much; Crowley wrenches away and keeps crying, but even with blurry eyes he can see Aziraphale scramble to his feet and toward the door.

"I'm sorry," says Aziraphale, his voice high with what might be panic. "I'm so sorry, Crowley. I thought, perhaps—I'm sorry."

Crowley looks up at Aziraphale in his doorway and cries harder, but he manages to say, "Nothing to apologize for, Angel."

"No, that was—that was over the line," says Aziraphale. Then he looks at the floor. "Just tell me if you never want to see me again, all right?"

Crowley can't get himself under control, but he lurches to his feet anyway and stumbles to the doorway. "Angel. I want to see you every day."

"But I kissed you," says Aziraphale wretchedly.

Crowley wants to kiss Aziraphale to show that he wants him, but instead he has to turn and sneeze. After that, he turns back to Aziraphale, who hasn't moved, and says, "And? I've only wanted that for millenia, Angel. Like I said, nothing to apologize for."

Aziraphale reaches for Crowley's hand, and Crowley gives it to him willingly, wonderingly. "You—you did? You do?"

"Of course," says Crowley. "You're perfection incarnate. How could I resist?" He pulls his hand from Aziraphale's in order to turn and cough into his sleeve.

When he turns back to Aziraphale, Aziraphale runs a finger hesitantly down Crowley's cheek. "Please stop saying that," Aziraphale whispers. "I'm so far from perfect."

"You're wrong," Crowley whispers back.

"But I accused you—"

Crowley rolls his eyes; it makes him dizzy. "So you drew a conclusion that turned out to be false. It's fine, Angel. You're always so perfect that I'm afraid to contaminate you; it's in your rare mistakes that I feel like perhaps I could actually have you."

Tears leak from Aziraphale's eyes. "Crowley, Crowley. My dear. You can have me any day of the week for the rest of our lives. It is I who could never deserve you. You've been so brave for me, Crowley. So selfless. So good. How could you ever think that you only deserve me when I hurt you?"

"I'm a demon!" says Crowley, louder than he meant to; it hurts his throat. "You're an angel! Why is this so hard for you to under—" He breaks off, coughing.

Aziraphale puts a hand on Crowley's back and steers him back toward the bed. As Crowley keeps coughing, Aziraphale pulls back the covers, dislodging untold used tissues, and guides Crowley into a seated position against the headboard and then pulls the blankets and sheets up around him. When Crowley finishes, Aziraphale whispers, "May I kiss your forehead?"

Crowley searches Aziraphale's face, finding nothing but kindness and worry. "All right," he whispers, and then there are cool, soft lips against his burning skin.

After a moment, Aziraphale draws back and says, "You know our sides mean nothing. Demons and angels—we're all the same stock, and my side was as bad as yours. You know this. You Fell. How could you think I'm any better than you?"

"Because you're you," says Crowley simply. His throat hurts so badly, and he can't help rubbing at his neck with one hand.

"And you're you," Aziraphale returns. "I suppose it's time for that tea, isn't it?"

"You don't need to—" Crowley starts.

"Shush," says Aziraphale, so gently. "Just rest, my dear. Let me do this. Please."

"All right," Crowley whispers, unable to bear Aziraphale's earnest expression.

Aziraphale leaves the room, and Crowley hears him fussing about in the kitchen. A minute or two later, he returns with a pad of paper and a pen. "A list for the chemist's?" Aziraphale asks, pressing the pen and paper into Crowley's hands.

Crowley just nods and begins writing, in too much pain to hazard talking.

Aziraphale takes the list when Crowley finishes it, and then he finishes making tea and leaves for the chemist's. Crowley drinks the tea, physical misery lessening very slightly, and cries a bit more as he replays Aziraphale's guilt-ridden expressions in his head. How could he have made his angel feel that way? But he can't let Aziraphale see him cry again, not when it might increase Aziraphale's misplaced sense of guilt, so he pulls himself together when he hears the door opening.

Aziraphale unpacks the medicine quietly, and Crowley uses the last of his tea to swallow the pills Aziraphale bought. Then Aziraphale takes the mug to the kitchen and returns to Crowley's bedroom and hesitates on the threshold. "Would you like me to stay?"

"Angel, you needn't—"

"May I?"

Crowley looks down and nods. The next thing he knows, Aziraphale has his shoes off and is pulling back the covers to join him in bed.

"We should talk when you're well," whispers Aziraphale, stroking Crowley's hair. "I owe you so many apologies. But for now, can you sleep?"

Crowley shrugs.

"Can you try? For me?"

Crowley nods. Aziraphale continues stroking his hair and intermittently kisses his forehead as well. And eventually Crowley drifts off.