Legend of the Guardians: The Owls of Ga'hoole

Well, I don't know exactly how the torches "go out", but I will say that if you get a gold medal on this mission, you should unlock the trophy. At least, this worked for me. (I got the gold ranking the first time, by the way.) To get a gold, you just need to finish the level quickly. (If I recall correctly, under 6 minutes 30 seconds).