[he doesn't over-do the welcome back, not to demean Cain, but so as to not make his dynamic with Cain feel similar to his dynamic with Birdman. no "you're lucky"s, no "anything for you", not right now.
keep it simple.
Rion reaches into his stupid fucking fanny pack and extracts a prescription canister. he raddles out a couple of pills, and extracts one from his palm.]
...I want you to take this, too. We're alone, and it'll help. They're giving it to me at the hospital for the withdrawal. You need it more than I do.
It won't make you better to the point of suspicion, but the pain and fever will stop... and when it comes back, it won't be as bad as quickly.