Well, kinda.

We have limited looks into what he was doing through the book but mostly he was in school. We (nly see him at the startin one of the meetings with Voldemort where he is clearly not comfortable. And then at Malfoy Manor where he refuses to identify Harry (or Hermione or Ron).

Also the book before when he had Dumbledore at his mercy, he was lowering his wand when other Dead Eaters marched in on him. He clearly had his doubts - no wonderv the whole Half-Blood Prince he was tortured with the impossible task he was given as a punishment to what his father has done and the whole year after they suffered Voldemorts displeasure by them.

And still, he went out of his way to serve. Honestly, I was not happy with this because I sensed his redemption arc coming and no he just became villain again. There is a cut scene from the movies where he throws Harry a wand and runs over from the Death Eaters when Harry reveals himself alive, which is something I think would be great for his character - to show that in the end he was a brainwashed boy who was victim of his upbringing but managed to overcome… but that’s not what happened.