“Remus, my old friend! Have you taken your potion tonight? You know...” – Sirius Black, Harry Potter and the Prisoner of Azkaban ... Movie Quotes Database

[trying to stop Lupin from transforming into a werewolf]

Remus, my old friend! Have you taken your potion tonight? You know the man you truly are, Remus! This heart is where you truly live! This heart here! This flesh is only flesh!

More from Harry Potter and the Prisoner of Azkaban

Cornelius Fudge Black was vicious. He didn't kill Pettigrew... he destroyed him! A finger! That's all that was left, a finger! Nothing else. Sybill Trelawney You see, the truth lies buried like a sentence deep within a book, waiting to be read. But first, you must broaden your minds. First, you must look beyond. Harry You see Sirius talking to me there? He's asking me to come live with him. Hermione That's great. Harry When we free him, I'll never have to go back to the Dursleys. It'll just be me and him. We could live in the country, some place you can see the sky. I think he'll like that after all those years in Azkaban.