The first novel of the “Captain Nemo” series (“The Children of Captain Grant”, 1867; “20,000 Leagues Under the Sea”, 1870; “The Mysterious Island”, 1875). The combination of these works into a cycle is largely conditional. Common characters link the novels 20,000 Leagues Under the Sea and The Mysterious Island (Captain Nemo), as well as the novels The Children of Captain Grant and The Mysterious Island (Ayrton). It's also interesting to note that 20,000 Leagues Under the Sea took place in 1869, while The Mysterious Island took place around 1865. This means that Captain Nemo died before he met Professor Aronnax.

During a boat trip off the coast of Scotland, which Lord Edward Glenarvan and his family took on his yacht “Duncan”, an unusual fish for these waters was caught hammerfish. A bottle containing a damaged written document was found in it. From the surviving part of the note, it can be established that Captain Grant, a brave Scot and famous captain, is asking for help. The official authorities of Great Britain refuse to help in the search for the captain - after all, the note was written two years ago, and the location of the crash is unknown, only an indication of the thirty-seventh parallel has survived... Then Lord Glenarvan himself goes to search for the captain with his family, the children of Captain Grant and a geographer who accidentally joined them Jacques Paganel. The heroes of the novel travel around the world along the 37th parallel in South America, Australia, New Zealand, in the seas and oceans in search of Captain Grant.