This is a difficult book to review. Well in one way its very easy to review – it's an excellent action story, with some clever set-pieces that essentially gives the Outlanders scenario a hefty kick. However when it comes to explaining why I hit a problem because that means revealing spoilers and the less you know about the plot, the more I think you'll enjoy this novel. Rik Hoskin brings to a head many of the ongoing storylines which he and the editors have been working on since “The Janus Trap”. So if you've read the last six books then you're going to get some added satisfaction but if you've been dipping in and out then don't worry, you won't be lost because all the information you need is there.

The Cerberus Redoubt is attacked and conquered by the brainwashed army of Ullikummis, the rogue Annunaki god. Kane, Brigid, Grant and their friends wake up inside stone cells with no doors. Weakened, defenseless and cut-off from each other, they begin to realize that their enemy wants to do far worse that kill them.

There's a real determination to challenge some of the series basic elements and refresh them that worked really well for me. For instance the Annunaki have regularly been described as being near immortal and multi-dimensional but this book really tries to describe and understand what that means. As Ullikummis tells Brigid scornfully, did Cerebus really think his race were just humans in reptile costumes? Rather like army training, this story is about the regulars been broken down to rock bottom, then slowly building themselves up again.

Some of the strongest scenes take place between the stone god and Brigid as he interrogates her, teaches her about his own race and forces her to face her hidden feelings about the imaginary daughter she had in “The Janus Trap”.

Describing the invasion of Cerberus in flashbacks is a neat device that keeps the plot moving forward whilst giving this event the detail and weight it deserves. There's a still room for a fair amount of gun play and fight sequences, which the author once again handles adroitly. By the end of the book the series as a whole is moving in a new, grittier direction and based on the classic “To be continued” cliffhanger I am definitely looking forward to finding out what happens next.

This was definitely one of the better Outlanders books I have read in a long time. While I was not too keen on Ulikummis in the beginning and his nearly indestructible stone hide, this book slowly changed my mind.

For Cerberus to be taken over was a jaw dropper. I don't think I/we ever expected this to happen in the fashion it did, considering their base was practically impregnable. But maybe this attack was the point: to show it wasn't impregnable and could be breached. And it was done in a great way: literally, an inside job. Members who had been implanted with the stone in the previous book(s) suddenly turned on their allies.

It was a shame to see some of the series regulars get killed off, but I guess it had to happen sooner or later. But by doing so, it removes characters that had been built up and given personalities and such. It removed...choice for future books, might be a good way of putting it.

The ending and revelation was definitely a shocker. I did NOT see that coming. But I won't spoil anything more.

In the summer of 2008 there was a very distinct shift in the style and direction of Outlanders, with the publication of the first book after the departure of series creator Mark Ellis. Where previously the series had been primarily a high-adventure storyline with liberal doses of hard science fiction, under the reins of new primary author Rik Hoskin the storylines retained the same kind of explosive action but tended more towards the esoteric in terms of science fiction content. He also began laying down some very slow building plot threads and new secondary characters. All of those new threads have lead to a staggering climax in Truth Engine.

The previous book had ended on a bit of a cliffhanger, with the Cerberus trio returning to home base only to find it in apparent disarray and under attack. Truth Engine does not pick up with that moment initially, but rather springs forward to Kane, Grant and Brigid all separately in captivity in solitary stone cells. The story weaves back and forth between their current incarceration and the battle that led up to it, gradually weaving in other perspectives from characters like Domi and the new recurring character of Rosalia. It is a slow burn with punctuated bursts of action as well as internal drama.

It is difficult to write a review for this story, because so much of what makes it shine are also plot points that would be significant spoilers. Suffice to say that there are shocking deaths, alliances torn asunder, and new alliances forged. Although it reads well as a standalone story, it also serves as not only the culmination of the previous three years of storytelling but also as a dramatic resetting of the stage for the next cycle of books. Every character has moments to shine, and even the mongrel dog Belly-On-Legs gets a very sly and memorable action beat. All in all, this is easily the best work Hoskin has done on the series to date. I thoroughly enjoyed it, and I am looking forward to seeing where the series goes from  here.