STORY
The title could look forward to another trip to the science fiction story that is constantly expanding since the first Ayreon album. However, the eponymous theory is just a McGuffin, only at one point dip corresponding physical concepts on. Clear that the "grand unified theory" (see Wikipedia) is not explained scientifically correct, because there's still not - and that would be determined even boring.
But what is sold here as a story is - sorry, Arjen - cheaper cliché trash.
We have an autistic child-genius who could help his father at work on the theory - this he would however take an untested drug. The mother does not want to risk the lives of her son; the father is only interested in his theory. The father then gives him secretly the drug, and he wakes up à la "Tommy". Then we have the "girl" and the "rival" that exactly behave as you expect.
Say: Instead of a continuation of the story about the planet Y, the Migrator, the Mars colonies - in short: instead of a science fiction story, there is time, "Rain Man". What is not always a bad thing, but then that would also "The Genius Inside" or so hot and not "Ayreon" shall stand over it (Arjen still has several other project identities).
MUSIC
4 tracks of 20 minutes each Arjen has come up. or rather, as already divided on the CDs: 42 fragments with an average of 2 minutes running time.
The problem is that just as it sounds often. Since then comes the next track going in a different key, so still has to quickly resolve a guitar run then, because otherwise there is no connection between the parts. The rhythm changes often unmotivated or too fast synth arpeggio droning for ~ 15 seconds before it is detached from the next track, the connecting up to the new tempo nothing with the arpeggio.
Such fractures may well fold times and listen to good (see, inter alia former Ayreon plates), but on the "Theory of Everything" I have too often feel that the parts have been knitted together with the hot needle. Partially also an accompaniment will be played only once in a different key (which still fits to the previous track) and then changed compositionally unmotivated in the key of the new track after 5 seconds.
I would have preferred to have individual separated tracks, as this pack on Devil come-out with each other to 20 minutes together, even if a not a reasonable reconciliation incident.
Unfortunately, with such a concept behind stuck fewer impressions as no longer suspense are present, such as in "Beneath the Waves" or "Isis & Osiris", the one therefore burn itself into memory. Only the title track remains in the memory.
The basic tracks are actually quite good - but by this Verhackstückelung and no clear line that runs through the 20 minutes of the individual parts, the listening experience is tarnished.
In addition, there are a handful of places, remember that much of past albums - partly I guess you could seamlessly guide piece in a known older Ayreon by appropriate crossfading. But I had also thought first in the "01" album and found it afterwards well, so I ignore it for evaluation.
CONCLUSION
Be sure to listen before even a full 20 minutes part to experience the action as a whole.