Professor Aronnax is invited on an expedition to find a giant sea creature responsible for eating a hole in a steel ship and almost sinking it. Having a passion for studying the sea, he gratefully accepts and brings his assistant along with him. On the ship, they meet Canadian harpooner Ned Land who will be responsible for taking the beast down. It takes a while, but they eventually find the monster and pursue it. When they get close enough they try a shot at the beast, it looks like it does no damage. The beast takes aim at the ship and Prof. Aronnax and his mate go overboard.
In the water, far away from the ship, they also find Ned Land clinging to what looks like a piece of the beast. But it's made out of steel, surely it's not an animal. Suddenly a door opens and they are brought within this ship and kept captive. The beast they everyone has been trying to pursue is an advanced submarine.
Being kept captive on the ship, the trio is allowed to partake in the adventures they go on. They see things no one but those on the ship have seen and venture to places no one has been. It's obviously Verne had an incredible imagination to pull this book together and, despite it being 100+ years old, still reads like something that could happen today. This is where the book excels, as the characters are a bit weak. There was no purpose to Aronnax's assistant in the book at all. He provided absolutely not value to drive the plot forward. And even the main characters like Aronnax, Land, and Captain Nemo we don't find out too much about.
Even with this, the book's weakest point is the ending. It's like Verne couldn't figure out how to end the book so just gave up and said oh well we're done now. It's unfortunate as otherwise the book was pretty fun.
First Line: "In the year 1866 the whole maritime population of Europe and America was excited by a mysterious and inexplicable phenomenon."