This is book 12 of the "Phryne Fisher" series.

This note contains spoilers for the book.

Now, this one I saw a TV episode based on.

Soldiers, friends of her friends Bert and Cec, are being killed, and it must relate to something that happened in Paris in 1918. Phryne was in Paris in 1918 herself (having served in the French ambulance service during the war), modeled for famous painters, bought modern art for her suddenly-rich fater, and had her heart broken by her first love. One of the artists was the man who was killed, and the question of who did it appears to be key.

Meanwhile, Lin Chung's family has found him a wife, allegedly a village girl from China (which is falling back into control of the warlords as the central government disintegrates in civil war). But the woman who actually shows up is much more educated. Then, this gets Mr. Butler all worked up, to the point of actually giving his notice (she's pretty scandalous by the standards of high society in 1928 in Melbourne).