Megan Davis is a smalltown civil litigator who dropped out of the world for a year after her husband died in a plane crash. Now back at her job and her house and her life, she finds herself faced with an old client, Jeremy Waldoch, who tells her a female former employee has brought a case against him.

It’s not Waldoch’s first defense. It’s not even the first defense Megan’s handled for him.

There was another one before. Another former employee. Another woman. Another set of claims arising out of sex, out of relationships gone bad, and – as Megan starts to discover when she digs into the new case – out of diamonds and deceit and murder.

But she’s not the only one looking at Jeremy Waldoch. Megan’s agreement to take the case sets her on a course that brings her to the attention of Jackson Hanley, a federal agent with an altogether different interest in Megan’s client.

Hanley’s task is to bring down the man who runs Laurentian Mines, a violently aggressive diamond mining company – a “glass house” – in a forgotten corner of South Africa. That man is Waldoch himself, and when Hanley can’t get Waldoch for what he’s done in Africa, he knows he’ll have to find a way to get him in the United States.

When all those worlds come together, Megan faces choices she doesn’t want and options she doesn’t like, ultimately finding herself in the middle of a battle between Hanley and Waldoch, truth and lies, and right and wrong – a battle that extends across continents and an ocean in a shattering series of events that may cost her everything she has.

I found the first part of the book quite good – the scans that every diamond mine worker has to go through but the jumps from Africa to Megan were quite abrupt. I much more preferred the story about the Laurentian mines than the legal battle.

The first mines in this region were beach mines, positioned where the rivers flowed into the ocean. Far back in time, when the seas were higher, the rivers had carried diamonds from the interior, tumbling them along the river beds. The heavier stones had dropped in caches, but the Orange and a few other bigger
waterways sent the smaller ones farther out, into the ocean depths.
When the waters receded, the larger stones were found in deposits along the coast. Mining companies staked their claims, built their facilities, and sent their trawlers out to sea. The companies dug the shores and sucked beach and seabed sand up by vacuum, combing the material for diamonds and dumping whatever didn’t pan out. The work of the mines resulted in the hills that lined the seaboard north and south of the Orange, and it gave the area its name.
The Diamond Coast.

In the mantle’s upper portions is a zone where the temperature is 1,000 degrees Centigrade, over 1,800 degrees Fahrenheit. The pressure is 50 kilobars, which is more than 700,000 pounds per square inch. That’s 500 times the atmospheric pressure on the surface of Venus, and it’s enough to disintegrate a human being. That area is the diamond stability field, where carbon is pressed into layers, and where those layers are pressed together with more layers until diamonds are formed.
That process doesn’t naturally occur anywhere else on the planet. Diamonds form only there, at a depth too far down and too dangerous for people to reach – no direct examination even of the Mohorovii discontinuity, the mantle’s
uppermost boundary, ever has been made.
Which means, in effect, that diamond miners don’t truly dig to the original source of diamonds to find them.The diamonds instead have to be brought to the surface first, where they can be dug out. That’s the work of volcanoes. More specifically, of kimberlite volcanoes.
Kimberlite volcanoes start deep in the upper mantle, farther from the earth’s crust than typical volcanoes. And when they erupt, they do so slowly at first.
Kimberlite magma, a plasma rock, moves upward at only around ten miles an hour. It seeks weaknesses in the rock above it, drilling and forcing a passage to the surface. And as it moves, it brings surrounding rocks and minerals with it,
including whatever it collects from any diamond stability field through which it passes.
At the end of a kimberlite eruption, the process speeds up. Kimberlite volcanoes erupt like typical ones, sending rock and lava into the air. But they send any carried diamonds up and out as well.

I feel like I’ve learned loads.