Darling, what is the morphine situation now? You have not mentioned it in ages. The last you said was that it was still necessary and would be for some time. Isn’t there something else you could take? I’ve been reading about morphine – the principal alkaloid of opium (if you don’t think I know what an alkaloid is, I now do!) Please watch it…
Her words struck a small pang of guilt in him. He tried cutting down. He could do on three shots a day, and he had been taking four. But he noticed the difference in his spirits: they weren’t quite as good, or as cheerful. He asked Dr Cassini for some Demerol or anything that deadened pain, and the doctor gave him something – something real this time. It worked, but it did not work as well as morphine, which, Carter very well realized, had a most pleasant way of changing reality into a form much easier to bear. For two weeks, Carter took no morphine, and then he began mixing his anodynes, depending half on morphine and half on the pills.
This story has a very claustrophobic feel to it, and it isn't necessarily the prison setting that makes it so. Highsmith's created several kinds of prisons for Carter here and it works well. The sense of anxiety that comes off the pages is almost tangible.