Nadia, Secret of Blue Water: Nemo's Fortress does not do much to advance the plot of the series. Sure, there are small advances through the episodes, but overall the audience is left at the end with the same questions as in the beginning. The narrator calls each new development in the story a clue in unraveling the mystery of the Blue Water gem, but the biggest clue given – that there is a connection between Nadia and Nemo – has been known since the beginning. It would seem that these four episodes are meant only to create further suspense and anxiety within the audience for finding out the answer to the “Secret of Blue Water.”

Typical of ADV releases there are very few extras on this DVD. There are only four character bios and one of those characters hasn't been seen since the first volume. A bio of Nemo might have been more entertaining, or perhaps schematics for the Nautilus? The ship has been a main feature since the beginning but we still don't know very much about it.

But the DVD is still worth the price tag. While the stories told do not advance the plot by much, they are still well-told. Jean's struggle to be seen as an adult is familiar to most teenagers, as is Nadia's jealousy over Jean and the first officer. Captain Nemo still comes off distant and cold but it becomes apparent that he has a soft-spot for Nadia and watching the evolution of their relationship is indeed entertaining. The question of what exactly the relationship between the two is should keep any fan involved in the series.
Grandis does not play as big a role in this volume as she has in the past but Hanson and Sanson have become almost like older siblings to Jean and Marie, offering advice and play when needed – a stiff contrast to the roles they started out in. These may be filler episodes in the grand scheme of the series but they are excellent at showing us just how much the characters have evolved since the first episode.

It is learned that the ancient Atlanteans had established a base in the Antarctic. Like the art of Atlantis itself in the previous volume, the backgrounds of Antarctica are the main attraction. The prehistoric animals frozen in ice are especially worthy of mention. The shadows and colors, along with the reactions from Jean and Nadia keep with the tradition of new experiences through the eyes of a child. The art of the series has been consistently good and this set of episodes continues the tradition.

Gargoyle finally returns in episode 19 but is more of a behind-the-scenes-man, setting up traps for the Nautilus in the sea while safely hidden away in the air. It does end with a great cliffhanger as Gargoyle's ships surround the Nautilus but lacks the sense of confrontation that is sure to follow in the next volume.