Birmingham's tale sprawls across several years, beginning with a catastrophic accident that tears a hole in time, throwing an international fleet from 2021 back to 1942. The uptimers emerge at night, slap bang in the middle of the US task force heading toward Midway Atoll. A major problem is a side effect of the unexpected time travel which causes most of the future crew to arrive unconscious, or barely functional. Sensing the danger, their computer controlled Combat Intelligence acts in defence when elements of the '42 fleet attack, quickly leading to all guns blazing on both sides. By the time the error is realised, the future fleet has decimated their 1942 counterparts, and suffered severe damage itself.

The impact of the uptimers arrival has many strands, which the author explores to fine effect and in both directions. That is to say, we get the perspectives of the culturally very different uptimers finding themselves at a pivotal point in their past, and the 'temps, (short for contemporary), characters reacting to the shock of having what to all intents and purposes is a wave of immigration from a world they don't understand. Future tech is a Pandora's box, including ship destroying missiles, metal storm anti-aircraft batteries, and flexipads, which are portable computers like PDA's, but with the power of a quantum desktop model. Birmingham's tech is every bit as well thought out and convincing as anything devised by Tom Clancy, and his plot rolls and pitches in a highly entertaining fashion. Huge cultural impact is caused by public access to Fleetnet, a vast digital archive that contains banks of future movies, all genres of music, and crucially historical material. It is fascinating to see how the 'temps deal with what was scheduled to be their future. Was, because the presence and actions of the 2021 forces cannot help but precipitate changes. Equally interesting is the social trials and adaptations required for the uptimers to coexist in their past. Not everyone is happy for them to be there. Remember, in 1942, no serviceman had imagined there would ever be a black colonel, or a British naval commander who is both a woman and half-Pakistani. Something that sets this work above most other alternate histories, is the author's meticulous attention to multi-culture, credible charactersation, and rapier thrusts of graphic violence to remind the reader of what a horror war presents. While the systems of destruction may be glamourised, their use is certainly not. As the opening novel draws to a close, the terrifying possibility arises that other elements of the 21st century task force may have fallen through time, and into the hands of the Axis powers.

"After all, who had created Bin Laden, the first of so many Islamist heroes? And whose appetite for oil had funded the Saudis, who in turn funded the madrassas of so many of the Wahhabi lunatics who had overrun the slums of Paris? It was the United States, Le Roux mused, who had turned the Middle East into a sinkhole of violence and islamist revolt thanks to its support of Israel, its occupation of Iraq, its bombing of Iran, and its wars against Syria and Yemen."

The problem here is that knowledge is not, of itself, the means to the end. Knowing how to construct an atomic weapon, is a long, long way from having the industrial infrastructure and level of science required. However, this does not stop all sides from making use of what fate has dumped in their laps, and the future tech is used decisively when required. But it is a finite resource that dwindles as the story progresses. The 2021 fleet was originally tasked to fight in a limited conflict, not a years-long global war. As supplies run out, compromises are made and weapons retrofitted. Similarly, the political and social landscape shifts like quicksand, as both sides struggle to adjust.

In the US, a special zone is created in California, where 2021 laws and customs rule, creating an environment for rapid technological development and cultural advancement. Not that J. Edgar Hoover sees it quite that way. In the free world, future history is widely disseminated, and used in all manner of ways for the advancement of companies, and individuals. Movie makers exploit their uptime creations, and one enterprising individual signs up the seven and half year-old Elvis Presley, whose lifetime recordings are already public knowledge. Birmingham also teases with glimpses of 2021 history, such as Hilary Clinton having been a US President who was even more hard line than George W. Bush. Meanwhile, in the Soviet Union, news from the future is tightly suppressed. Stalin exploits his knowledge ruthlessly, thinking nothing of using up millions of lives to advance his atomic program, while the ceasefire gives him time to prepare for a decades long struggle against all who would oppose Communism. In Germany, the secrets of the future are also kept hidden, available only to the trusted few, and used by the SS to eliminate the entire families of anyone revealed to have been less than 100 percent committed to the Nazi cause. Information, above all, is shown to be power. But how, where, when, and by whom that power is applied makes all the difference. Encompassing politics, social engineering, technological advance, and the sheer brutality of conflict, Birmingham writes an almost perfectly balanced middle book.

"Do not tell me what is possible and what is not. You have boasted often enough about the impossible tasks you have achieved on Projects One and Two. Surely building the bomb was the major impossibility. I would have thought dropping it posed no problem at all. It is just a bomb after all, Beria. It is meant to be dropped upon someone, yes? And please do not tell me otherwise, or I shall have you nailed to the thing when it goes off."

Even then, the author has fun showing that what you see is not necessarily what you get. Heroes can sometimes be zeroes, and as for the zeroes, well, even they have feelings. Are there problems? Yes, but none that present major stumbling blocks. When compared to what has gone before, Final Impact feels a little rushed, leading to significant events such as the Final Solution being mentioned, but not dealt with as a priority, which can seem odd from the perspective of the future characters. Perhaps if Axis of Time has been planned as a four book sequence, there would've been room. I was also unconvinced that a large, 2021 multinational task force, including submarines and a giant aircraft carrier, did not come equipped with a handful of nukes. But, of course, if they were, the story might have been much shorter, and consequently nowhere near as entertaining. Other minor issues concern the use of Victoria Beckham's voice, for an AI called Posh, and the recurring character of Prince Harry Windsor, who in 2021 is an SAS soldier. Posh, probably seemed like a good joke at the time, but ends up scratching credibility. Prince Harry as an heroic, major character, was always going to be a risk, and falls flat on its face now the world knows the real Harry is a toy soldier. But, these quibbles aside, the Axis of Time trilogy delivers handsomely on almost all levels. The good news is that another two novels in the same world are planned, the first a prequel, set on this side of the wormhole, before the task force is thrown back to 1942, and the second set around a decade after events depicted in Final Impact.