The novel centers around a group of high school students living out in the Mojave desert. The female lead (Noor) came from Pakistan after her family was killed. She lives with an uncle that can be cruel and desires that she stay to work in a liquor store rather than go to college. The male lead (Salahudin)has decided to sell opioids to help his hotel-owning family through financial hard times. The other characters are bit players to be foils to the leads (such as the racists valedictorian, the single mother drug addict). There is a huge amount of suffering to go around, both external and internal. I felt sympathy for the characters as they tried to navigate situations and cringes when they made mistakes.
This is the fourth book in the Ember in the Ashes series. Two young people manage to overcome all sorts of supernatural challenges to finally express their love for each other. Everyone else is pretty much background.
I thought this was the final book in the Ember in the Ashes series. It did seem to wrap things up, however it did it in a very unsatisfying way. The evil ones always seem to be a step ahead of the good guys. The characters are primarily in hard-core "war" mode. There is little time for caring for others. Often time spent loving others causes more negative than good. The struggle of the boy that is the "Reaper in training" is especially prescient. He must learn to not love others in order to use his magic to "reap" the dead into the after life. His failure to let go of love to others led him to neglect his duties, and with that neglect he gave enemies a chance to hurt his friend. 
A Torch In the Night continues right where the first book leaves off with the two leads running away. There is plenty of violent activity. Many of the characters are conflicted between loyalty towards the imperial oaths and individuals. This book gets a little more "magical" than the first book. The connection between the current world and the afterlife is explored, with somebody gaining some power there. One girl learns to better control her ability to remain invisible. People sacrifice their family for the good of the empire, even though it is obvious that it is in poor leadership. There is plenty of romance on all levels. While some characters are fairly complex, others can be much more black and white in the "good and evil" department. The novel alternates the first person perspective among a number of these characters. Overall the book feels dark with flames burning. "A torch against the night" is an adequate description.
Ember in the Ashes follows the experiences of a few young adults in a world similar to the Roman Empire. One boy is the illegitimate son of the the commandant. The commandant had tried to abort her pregnancy, but ended up just abandoning him to local people, only to have him come back. He is an aspirant to the emperorship. The other main character (and eventual love interest) is a girl, part of the "scholars" who are involved in a rebellion. She sells herself into slavery in the commandant's house as a means of freeing her brother from prison. There is plenty of double-crossing going on. The two characters eventually fall in love. However, they both also have other good friends with romantic intentions. The "trials" to produce the next emperor force the characters to engage in horrible acts, including the killing of one's own friends. Eventually, the two characters manage to escape. The book ends with their escape, leaving the next book to pick up right there. There is some magic and fantastical elements. However, the book is primarily about psychology and family relations.