Shira has lost custody of her son to her husband, and has left the Y-S "multi" that employs her to return to her home "free town". One of the town leaders, feeling danger threatening, has built Yod, an illegal cyborg (full artificial intelligence in a human shaped vehicle) to defend them. But Y-S is after Yod... The narrative contains enough political intrigue, biologically enhanced assassins and data piracy to keep the cyberpunk fans happy, but it also has some serious meat in it. It tackles head-on some of the philosophical and ethical dilemmas likely to be involved in the development of artificial intelligence.
Interlaced with the main story is a secondary narrative. This is the story (as told to Yod by Shira's mother Malkah) of a Jewish Rabbi in 17th century Prague who creates a clay golem to defend his people from a threatened pogrom. This sub-story is both simpler and bleaker, but has the same compelling drive as the main story, and the two complement one another superbly.
I can't recommend Body of Glass too highly. It is one of the best science fiction novels I have ever read, though Marge Piercy's earlier Woman on the Edge of Time perhaps had more of a bite to it. Now I have to go and find the rest of her novels...