This was a decent bit of self-insert fanfiction. It was not a good book.

There's almost no room to breathe and get to know our main character before he's thrust directly into the plot. A lot of characters are introduced in rapid succession with very little to tell them apart, and then that entire plot is dropped within a handful of chapters, and an entirely new story begins.

For a book that advertises itself as a multi-Doctor story, we spend drastically different amounts of time with different incarnations, and a disproportionate amount of time with previous Doctors' companions and villains. The Eighth Doctor has very little interaction with any Doctor other than the Sixth. It feels as though the author wanted to place himself in Eight's place and spend some time with all the other Doctors.

The amnesia is severely under-utilised. I didn't get the sense that there was anything actually wrong with the Doctor.

Even the multi-Doctor plot is disjointed. Each of the longer parts individually would make very good epilogues, and the characters are very well written - the author clearly knew how to write them - but a bunch of good epilogues do not a good novel make.

The part with the Sixth Doctor was by far the best, and the only part of the book that actually felt like a novel. The Gallifreyan plot was weaved into the rest of the book and came to a satisfying conclusion (even if the inclusion of the Master was somewhat gratuitous). I enjoyed the politics and the worldbuilding.

The ending is just as jarringly short as the beginning, and Sam's transition into a companion is severely lacking.

It's possible I would have enjoyed this book more if I was more familiar with the other Doctors. As it stands, I had only reached the Third Doctor's era before reading this, and I didn't feel that his part was particularly relevant, even if it was good.

There's also the matter of formatting: any digital version of this I could find had the same strange errors where lines would cut to a new paragraph in the middle of a sentence. Practically every line had this issue. I got used to it, but I can't say it made for a particularly pleasant reading experience.