Phil knows by the Lee mission.
It's an extremely strange mission, the purpose of which Phil only vaguely understands, but that's life working under Nick Fury. The part that's important here is that Clint comes back with a bag full of prescription bottles- all different names, all different pharmacies- that he thinks Phil doesn't know about. Maybe he knows Phil knows; Phil doesn't know how Clint could think he doesn't.
Phil finds out in Bratislava.
Bratislava makes a whole lot more sense, in and out, just like they're accustomed to doing. Except that Clint gets captured, captured by people who know what they're doing. They hold him for six days, and in six whole days Phil can't find him, not even with his best people on the job.
They find him on day seven.
Shit goes haywire on day seven.
Day seven is when Phil pulls his favorite "We know you're in there and we will bury you" PA system trick, something he dearly loves doing. Not five minutes later Clint comes running out of the warehouse where they've been holding him, all of a sudden; he's got hell following him, half a dozen guys shooting. They're not shooting for long, not with Phil to give the order to take them out.
Clint looks behind him, and when he realizes he's not being chased, he comes to a stop, bending over with his hands on his knees.
It takes Phil a second to realize that he's laughing.
Phil's there with him in a heartbeat, and Clint is still laughing. "Did you see that shit, sir?" he says.
"I saw you almost get yourself killed, Barton," Phil says.
Clint laughs again, harder. "They couldn't have killed me," Clint tells him. "I could've taken fifty of them." His eyes are feral, and he's grinning. "Take you too if you don't get out of my way."
Clint's face is starting to pale, his breath coming heavy and labored, and Phil spots a trickle of blood running down from his shirt sleeve. "You're coming with me," Phil tells him.
"I'll go where I want," Clint says.
Phil sighs. "We can do this the easy way, or we can stand here and I can wait until you pass out."
Clint laughs again, and it's getting increasingly desperate, breathless. "You're going to be waiting for a long time, Coulson," he says. "I can't-" He blinks, swaying. "I'm- oh, fuck-"
Phil catches him, guiding him to the ground. "I need medical," he says into his earpiece.
Even after medical lets him go, Clint's sort of in and out for another day and a half. He'll let Phil help him shower, get up to use the bathroom, eat a few bites, but then he's out like a light again. It's good and bad; he looks like he needs it, like they all do after long, tense situations, but it's hard to sit there waiting.
Phil's there when he finally wakes up for good. Clint looks around, blinking; he looks down at the pajamas he's in. "Why am I wearing your clothes?"
"You don't have pajamas," Phil says. "I wasn't going to leave you there in your boxers."
Clint frowns, lifting the waistband of the pajamas and looking underneath it. "Why am I not wearing my boxers?"
"The clothes you were in were a loss," Phil tells him. "I draw the line at putting you in my underwear. Hungry?"
"Starving," Clint says. "What time is it?"
Clint glances at the blackout curtains. "AM or PM?"
"AM. I'll make you a sandwich."
When Phil comes back from the kitchen, Clint is standing in front of Phil's dresser, trying to find a shirt that fits- a losing battle, given how much broader his shoulders are than Phil's. "You're not leaving here for the next five days," Phil tells him, setting the plate down on the nightstand. "If you level off, we'll just call it good, but if you don't seem better, there are people I'll call."
"I'm not sure what you think is going on here, sir," Clint says; saying 'sir' when they're not working is a very efficient little 'fuck you,' especially when they've been together since those four hectic days in Laredo. "But you can't just-"
"I know what Depakote and Lamictal are for," Phil says; Clint doesn't say anything, just looks away. "You can't mix these drugs without periodic blood tests," Phil tells him. "The levels have to be monitored."
"How do you know about this stuff?" Clint asks.
Phil shrugs. "The Epocrates app is free for StarkPhone."
Clint looks down at the shirt in his hand, avoiding Phil's eyes. "What does medical think?"
"That the toxin you were exposed to was extremely fast-acting and that it was metabolized before they could get the bloodwork done," Phil says placidly.
Clint raises an eyebrow at him. "So they think what you told them."
"Many people around here do," he says dryly. "It's a specialty." He pauses. "I take it you're not going to be willing to get prescriptions from the doctors here."
"I somehow doubt that would be a good plan," Clint says, sounding a little snide.
Phil nods. "How fast to the pills expire? Do you need to stockpile more often?" The corner of his mouth ticks up. "I don't want to see you knocking over pharmacies."
Clint looks up at him, his mouth set in an angry line. "Just because I have a problem doesn't mean I need to be mothered."
"It's not my job to mother you," Phil says, not offended. "It is my job to stop you from doing dangerous things when they're unnecessary. And it's not a problem. It's just how it is."
"You can stop it, okay?" Clint says, clenching his fists around the material in his hands. "You can quit acting like this is alright. You can." He looks down. "You can quit acting like you don't want to go."
"If I wanted to do I'd have gone already," Phil says. "Clint, you have broken orders, lied to me to my face, blown operations-"
"Is this supposed to be helping?"
Phil doesn't stop. "If I could deal with all those fuck-ups, I don't know why you think I can't deal with something you don't have any control over."
Clint gives him an icy look. "I'm not out of control."
"Didn't say you were," Phil says. "Actually, it looks like you're keeping it under control pretty well, given the circumstances."
Clint shakes his head. "I never know what to make of you."
"Nobody does," Phil says, smiling.
Clint snorts. "Another specialty."
"Cultivated through years of practice," Phil tells him. "There's stuff you'll always keep from me, and that's fine. But it doesn't have to be everything." Clint nods mutely. "For now, you're ruining my collar."
Clint looks at the shirt in his hands. "Shit, sorry," he says, setting it down on the dresser.
"Don't worry about it," Phil says. He walks over, pulling Clint into his arms. "Eat. Rest. Take your meds. You'll be okay."
"Yeah," Clint says, letting Phil hold him. "Yeah."