Full disclosure: I received this book for free in exchange for an honest review.

In this book, Charlie and company are back in the future, but a farther future for Earth. Earth was invaded and thanks to the help of another race of four armed aliens, they prevailed against the invaders. Not a lot is shed about the invaders aside from them being bad, wanting to invade Earth, and decimating the human population. They do have a different race of aliens that obey orders from the invaders. AIs (Artificial Intelligence) now run the major systems and help humans live and coordinate activities.
Charlie utilize the help of the AIs, humans, and friendly aliens to find the dragon and free her.
Did I also mention there are cyborgs? There are. Except they aren’t cyborgs. The author needs to look up the definition of a cyborg. A cyborg is a being with both organic (human) and metallic body parts, think Robocop. The author confuses cyborgs with androids. Androids are robots with human appearance, think Data from Star Trek or the Terminator. Data can remove and replace the skin, arms, legs, and other components of his/it’s body, while losing any component for the Terminator will not greatly affect it aside from its CPU. Robocop can only replace the robotic parts of his body, he cannot replace the human components: his brain, heart, or head. In this book, the androids disguised as cyborgs make references to replacing the damaged human components. Like they were changing the oil filter on a car.
Then, the “Assbrew” makes an appearance; that is what its sounds like the narrator is saying. Its the name of the ship that Charlie was originally helping engineer. This plot point is just ludicrous in the extreme. So, the planet and humanity is recovering from a war were the majority of humanity is wiped out. Yet an unidentified spaceship, with a resemblance to a ship in the past, makes an appearance and when they hail the ship and it doesn’t respond, they just let the ship land. Really?!?!!? That makes absolutely no sense. Did all of the intelligent humans get wiped out in the war? Does the AI not have rules to preserve humanity?
Then, when the ship lands and people go to explore the ship, they trigger a spell that freezes all of the organic beings on the plant; the entire planet. All humans and aliens are frozen, with the exclusion of the androids masquerading as cyborgs, the AIs, and the majority of the protagonist’s party. How is it powered? By the hair of the aliens whose only magic is in their hair. Ok, but the spell is continuous. And affects any humans/aliens that come to help from outside the planet. Fine, fine, fine. How is it powered since its a continuous spell? The hair is absorbing the energy of Earth’s sun. It apparently apparently re-energizes the hair. Wonderful…. How? All of the hair is woven into parts of the ship and hidden. Since its hidden in the ship, its not the sunlight since the hair doesn’t get any of that. Then it must be radiation. Except its a spaceship. The kind where human travel in. Those kinds of ships have to have radiation shielding or people would get killed from radiation. Perhaps the metal used by whoever sent the ship doesn’t block radiation. Perhaps. However, radiation is weaker when it has to pass through materials and there was still plenty of the original ship. This then leads to more questions. As Charlie is an engineer and there are powerful AI around, how did they not immediately piece this together when it was revealed the spell was continuously being powered? Second, how did whoever sent the Assbrew know the hair could absorb enough power to power the spell? Massive plot holes are introduced one book after another. Still no explanation of how people are learning the magic words and intonations to make the exact spell needed for the needed plot point. It was explained earlier that no one knows all of the words for magic and the knowledge was lost, and ones that know more than others guard and hoard their magic carefully.
Later it is found out that a group of mercenaries from the previous universe Charlie was in, has come to Earth and has been abducting people. With AI all over the world and all the tech available, it should have been easy to track the aliens ship. The magic has to be cast for very specific circumstances. The stealth spell used for the mercenaries’ ship hides the ship from view. But there is a multitude of ways to find the mercenaries; such as heat, ultrasonic, and light to name a few. The mercenaries have never been to Earth or had to deal with the AI, so how would they know to prepare spells for this? Another plot hole that would have condensed the book down to a few chapters. If one AI can do massive calculations and provide different contingencies for plans, they can get together and do some massive data crunching to find a ship.
Everyone bows to Charlie and his strategies and advice when difficult situations arise. This seems off as his knowledge is old (both from tech and military side), he doesn’t have extensive military tactics training, and his magic knowledge is lacking. Why defer to someone in this situation?
Then, when they were fighting the mercenaries, they started using ballistic weaponry and they developed a counter for them. Then, they developed a spell for blocking lasers and plasma all while fighting. But they couldn’t block the power of heavy ordinances; heavy cannons. This is also off putting. It just seems you can cast a spell once and have it persist without using any energy from the user from then on. How does the enemy even know what is being fired at them? If they haven’t dealt with technology before, how would they know what a laser, plasma, or a bullet is? You would need to dissect a wound or corpse to extract the bullet. Or its a broad spell that blocks all physical items? If that is the case, how does some mercenary know that spell, because that seems like a very powerful spell. Also, how is there not even more weapons from the war? How is there not space stations/ships that can attack from space?
It looks like a new teenage member might join the team. Ok. The problem, they started teaching her magic. How can she cast magic when no one on Earth had magic potential? It was a combination of knowing the words and intonation, in addition to having magic talent.
Finally, the ending. What silliness. They finally cover the ship in lead and move the ship into space. It was revealed that if they try to damage the hair, the ship would explode. They then move the ship into the sun which it opens a portal into the sun. Apparently, Bob and the dragon come up with a spell to shield the Assbrew from the sun by siphoning power from the hair. How is it shielding from that much heat? Much like a bullet from a rifle/pistol cannot be compared to a canon, the heat from anything on Earth doesn’t hold a candle to the continuous heat of the sun. How is it shielding from that much radiation? Too much radiation will kill living organisms. These points all just seem to not even be considered.
I’m glad this will be the last book I listen to in this series. I had hoped for more. But unfortunately, that wasn’t the case. If you can ignore plot holes, then this book might be a decent listen. But the plot holes and leaving so many loose ends, as others have said, is not enjoyable to me. 4 books in and still don’t know what caused the original accident.
Narrator was ok. Would have liked a bit more variation to the voices.