This book is full of action and fantasy. Written by Ashley Poston, the book is composed of four perspectives:

Ana, found abandoned, was taken in by a rebellion crew. She has no memories of her life before.

Di is what’s known as a metal (or, robot). Di is Ana's best friend and he was found with her. Like Ana, he has no memories of his life before or the events that left him orphaned.

Robb is the younger brother of Eric who is to be crowned king. Robb is desperately looking for answers about his father's death.

Jax is a solani (pilot) who carries on the lost tradition of reading stars... and the future.

The novel starts off with a simple quest to save Di. Ana steals coordinates which were purchased by Robb, to find a chip that could save Di's life. Ana's plan hits a curve when the royal guards try to seize her for her theft. With the help of Jax, she and Di escape back on to the ship with the prisoner, Robb. With Robb as their hostage, Ana, Di, Jax and the rest of the crew follow the coordinates to Cerce, a dangerous part of the universe. Though Robb is angry about being a prisoner, he realizes he can still follow the coordinates to Cerce and find out if his father is still alive. Robb goes rogue when they enter Cerce, however despite all his hopes and effort, his answer is an ugly one. Meanwhile, Di sacrifices himself to save Ana's life. Because of Di's sacrifice, the crew was able to leave Cerce. But that isn’t the end of the story. Robb's mother, the queen, finds them and captures them to be brutally punished. But then Robb announces that he has discovered that Ana is the lost princess and true heir to the throne. She is the girl of light who was prophesied to banish the darkness. Since the moment of truth, the kingdom is in a tailspin. Preparations for Ana's coronation are made but Ana isn't satisfied. She wants more answers to what happened that night when she was found abandoned. An unexpected alliance with Robb pushes her to find out what really happened the night she and Di were found. Or really, who was responsible. The kingdom is set into chaos and war just as Ana discovers the truth. Near the end of the book, Ana, Robb, Jax and the rest of the crew flee the destructing kingdom until a surprising betrayal pushes Ana to save the kingdom. Just as was prophesied.

Heart of Iron was such a joy to read. It was quite the page turner and written with such strong emotions of love and friendship. I couldn't get enough of it. The end is such a cliff hanger that it will make you wonder what happens next. The setting and world building were so creative. The author did an authentic job of inventing cultures, history and divisions among the citizens. I'd recommend it to teens who love fantasy and themes of love and determination. The characters and plot were all written and expressed effectively in my opinion. The main protagonist Ana is such a lively character. She is strong, quirky and affectionate. Heart of Iron is definitely worth the time to read.