Man, it's kind of a trip seeing people asking about 'a torch against the night' before they even get the author's name straight. That's how memorable Sabaa Tahir's 'An Ember in the Ashes' series is, though. She wrote the whole quartet. 'A Torch Against the Night' is the second book in it.
It's this brutal, beautiful fantasy world inspired by ancient Rome, and the title itself is a perfect fit for the story—it's all about holding onto hope and fighting back in a super oppressive empire. People usually find her through the first book, so it's interesting when someone hits the sequel title first. Makes me wonder if they saw a cool fanart or something.