This is book 3 of the "Solar Clipper Smuggler Tales" series.

This note does not contain major spoilers for the book.

Natalya and Zoya, still out in Toe-Hold space 5 years later or something.

They visit Zoya's parents, who are maybe a bit richer than we've previously thought (the 5 billion to give Natalya her own freight company including a brand-new custom Barbell is described as small change).

And are there when news of a disaster on one of the other Usoko Mining smelter operation arrives. They go off to try to help, and find things and figure things out and get other people to contribute and help. The end!

It's a strange, short, side-series, and many of the plots are weird. They don't really relate to each other much in my view. Still fun though.

We do end up with Zoya taking over management. Her mother dies and her father retires (wise move, as they were a team and he was more the counterbalance, not a good position to try to take over and do it all yourself while dealing with grief).