Flashback: Keeper of the Lost Cities, Book 7

Difficult choices where all the options are bad come up often. Strong messages of friendship, family, loyalty, kindness, courage and self-sacrifice. Working together with people you don't especially like, and the importance of everyone's skills, talents, abilities, and differences in trying to do good things, and cooperating for good results.

Much of the plot involves Sophie and her friends determining that they have to become skilled with weapons and be prepared to use them to kill enemies -- and characters meet violent death.  As in earlier books, the teens suffer life-threatening battle injuries that test the limits of elvin medicine. Often the danger and damage are physical, as scars accumulate, bodyguards perish, and innocents are in constant peril. Mental violence, from erasing people's memories to inflicting assorted terrors, also plays a crucial role.

Frequent references, often humorous, to poop, pee, farts, butts, etc.

Potions and elixirs are just part of life. Teen characters ingest a stunning amount of (usually gross or foul-tasting) elvin medications. Sophie, who makes a point of avoiding sedatives, has to take them anyway as part of her recovery from near-fatal battle injuries.