… I see the confusion. The word “recover” has two meanings: an intransitive one in the sense of “heal” (which is what you understood – for example, “the soldier recovered quickly from his wounds”) and the other in the sense of “retrieve, get back” (which is what is meant in the extract – for instance, “they recovered the lost treasure”). The “operation” in question is not a surgical one, but a body retrieval mission. Hence, the person had already died, and they were on a mission to get his body back. Hope this helped!

Hi! The 'who' in the sentence modifies the adjective 'one' in the phrase one of the martyrs. (Please note that a martyr is a person died fighting in a war or battlefield). Hope that helps.