This was a genuinely great read.  I loved this take on the Silurians as we see an alternate Earth where the Sea Devils, Silurian, and human races have all united and are living peacefully.  But all is not well, as the Doctor of this universe has been assassinated and monsters are brutally attacking all over.  So the Seventh Doctor of the Prime Universe, Ace, and Benny all come to this alternate reality to investigate.  I love the creativity of this setting and it is realized visually by a tremendous artist named Colin Andrew.  It would be almost perfect, but the villain and confrontation around him was definitely underwhelming, while some of the dialogue and pacing were a little off.  Still an outstanding read and definitely worth anyone's time just because of how fun an idea it is and how cool Ace gets to be in the first couple parts of the story.