Meaning of "... when I was struck down by enteric fever, that curse of our Indian possessions," from A Study in Scarlet

Question

Worn with pain, and weak from the prolonged hardships which I had undergone, I was removed, with a great train of wounded sufferers, to the base hospital at Peshawar. Here I rallied, and had already improved so far as to be able to walk about the wards, and even to bask a little upon the verandah, when I was struck down by enteric fever, that curse of our Indian possessions.

I translated it verbosely as chunks like below:

1. Watson was very tired because of the pain caused by the Jezail bullet. And he was weak because he had undergone prolonged hardships in the battle, perhaps where he got shot.
2. He was removed along with many other wounded sufferers to the base hospital at Peshawar.
3. In the hospital, he recovered (rallied) and had already improved so far that he could walk about the wards and could even bask a little on the verandah.
4. It was all going well until he became very ill (was struck down) by enteric fever. Enteric fever was a curse of Indian possessions of England.

I believe 1 to 3 is accurate. How accurate? Don't know. If there is any inaccuracy, please let me know.

"Here I rallied, and had already improved so far as to be able to walk about the wards, and even to bask a little upon the verandah, when I was struck down by enteric fever, that curse of our Indian possessions." What is "when" doing here? Is it joining the sentences in the way I did on 4? And what's "... that curse of our Indian possessions"? Is it an absolute phrase? What is "that" doing here? Was it supposed to be "the"?

Answer 1

I don't see a problem with your interpretation of the text.

"Here I rallied, and had already improved so far as to be able to walk about the wards, and even to bask a little upon the verandah, when I was struck down by enteric fever, that curse of our Indian possessions." What is "when" doing here?

It indicates that what is being described was interrupted by what comes next. An example phrase could be "I was eating dinner when my cousin shouted my name".

what's "... that curse of our Indian possessions"? Is it an absolute phrase? What is "that" doing here? Was it supposed to be "the"?

"An absolute allows us to move from a description of a whole person, place, or thing to one aspect or part", so yes, I would say it's an absolute phrase. I would say the purpose of the phrase is to express in a poetic way that "enteric fever" was a very specific curse that came with the "Indian possessions", meaning that it's something problematic that directly follows the ownership of India.

Starting with "that" is also stylistic and somewhat poetic. Here's an example of how it's used in an English translation in one of Henrik Ibsens poems:

Had you sought a foreign strand, 
You would longingly be ferried 
To that old and cherished land