Final answer:
Lev saves Connor and Risa by threatening to detonate explosives strapped to his body, creating a diversion that allows them to escape the 'unwinding' process at the Happy Jack Harvest Camp in the novel 'Unwind'.
Step-by-step explanation:
Lev saves Connor and Risa at the school in the novel "Unwind" by Neal Shusterman through an act of self-sacrifice. As the narrative climaxes at the Happy Jack Harvest Camp, Lev arrives wearing explosive devices strapped to his body, threatening to detonate them. Recognizing Lev's dangerous situation, Connor tries to calm him down. It is during this tense moment that Lev has a change of heart and uses the threat of the explosives to create a diversion that enables Connor and Risa to escape the camp's imminent "unwinding" process, which is a method of organ harvesting. Lev's actions, driven by his growing sense of morality, not only save his friends but also disrupt the operations at the camp.