The Tower of Babel is the greatest marvel in the world. Immense as a mountain, the ancient Tower holds unnumbered ringdoms, warring and peaceful, stacked one on the other like the layers of a cake. It is a world of geniuses and tyrants, of airships and steam engines, of unusual animals and mysterious machines. Soon after arriving for his honeymoon at the Tower, the mild-mannered headmaster of a small village school, Thomas Senlin, gets separated from his wife, Marya, in the overwhelming swarm of tourists, residents, and miscreants.

A siege is approaching, and the city has little time to prepare. The people have no food and no weapons, and the enemy has sworn to slaughter them all. To save the city will take a miracle, but what it has is Orhan. A colonel of engineers, Orhan has far more experience with bridge building than battles, is a cheat and a liar, and has a serious problem with authority. He is, in other words, perfect for the job.

Humanity is running out of options. Habitable planets are being destroyed as quickly as they're found and Naira Sharp thinks she knows the reason why. The all-powerful Mercator family has been controlling the exploration of the universe for decades, and exploiting any materials they find along the way under the guise of helping humanity's expansion. But Naira knows the truth, and she plans to bring the whole family down from the inside.

In the first book of a visionary fantasy trilogy with its roots in the mythology of Africa and Arabia that “sings of rebellion, love, and the courage it takes to stand up to tyranny” (Samantha Shannon, author of The Priory of the Orange Tree), three women band together against a cruel empire that divides people by blood.

There has always been a darkness to Ilmar, but never more so than now. The city chafes under the heavy hand of the Palleseen occupation, the choke-hold of its criminal underworld, the boot of its factory owners, the weight of its wretched poor and the burden of its ancient curse. What will be the spark that lights the conflagration? Despite the city's refugees, wanderers, murderers, madmen, fanatics and thieves, the catalyst, as always, will be the Anchorwood–that dark grove of trees, that primeval remnant, that portal, when the moon is full, to strange and distant shores.