Janni's daughter gets shot down in World War Two and taken to Berlin, aka. Fritz Lang's Metropolis. There, our pirate anti-heroes meet the robot Maria and the doctors Mabuse and Caligari, plus Nazi zombies.
Oh, and also Adenoid Hynkel (Chaplin's parody of Hitler from The Great Dictator) and Ayesha.
It's pretty cool. "Captain Nemo attacks the Nazi capital" already sounds cool, but the book keeps topping itself with more danger, death and scarier baddies than you'd imagined.
There's a strong family angle. Janni has a husband (Broad Arrow Jack), a daughter (Hira) and a son-in-law (Armand Robur, the son of Verne's Robur the Conqueror). They love each other, but they're all pirates. The world rightly fears them and this book introduces them with a splash spread of fire, slit throats, severed limbs, axes, impalings and hooks in eyes, cheeks and ears. Don't expect them all to survive, but you also shouldn't expect them to go quietly.
Hildy Johnson returns too, in another bonus text feature at the end. Godzilla's mentioned.
Definitely recommended. My Nemo trilogy reviews are shorter than my earlier League reviews, since these stories aren't challenging the conventions of storytelling or anything like that, but they're exciting, cool and emotionally rich. The trilogy's on a roll.