Human Rites By Juno Dawson - Her Majesty's Royal Coven #3

Niamh, Ciara, Leonie, Elle and Theo. Five very different witches with one thing in common: they were unwittingly chosen by the dangerously charming Lucifer, the demon king of desire, to fulfil a dark prophecy: Satanis will rise and the daughters of Gaia will fall.

The coven is reunited--but broken. Niamh is back from the dead...but she hasn't come back alone. Elle mourns a son she never had. Ciara languishes in a prison for witches, and Leonie reels from a very unexpected surprise.

Meanwhile, Lucifer offers fledgling witch Theo a deal: if she helps him, her coven--her family--will be spared. But the magic he asks for will take her out of London--out of time, entirely.

The final confrontation between good and evil in the spectacular conclusion to the saga of Her Majesty's Royal Coven.