Marcus and Phoebe are to be mated, but first Phoebe needs to become a vampire. She must be separated from Marcus as she learns how to control her new body and thirst for blood. As Marcus waits out the separation with Diana, she gets him to speak of how he became a vampire, his past spanning the American and French Revolutions.

Time's Convert works as a companion book for those eager to revisit the world and characters of the All Souls trilogy. I liked the details of Diana and Matthew's domesticity with raising their kids. The "birth" of a new vampire seems to be something which draws together all the family members meaning you get cameos from most the surviving cast.

The book alternates between, Phoebe and Diana in the present and Marcus in the past. Phoebe spends most of her time indoors, until she stops being light-struck, and her part explores the mythology of the vampires in this world. It's quite detailed in the process of learning how to be a vampire without much dramatic tension, other than worrying about the cat.

The substance is provided by Marcus' backstory. You can tell Deborah Harkness is a historian as it encompasses a lot of historic details from the American Revolution, which was where Marcus came into contact with Matthew. There was pestilence, injury and death in abundance and here he became known as Doc, despite not being a real doctor.

The parts told in first person are from Diana, who is dealing with the fact her children are coming into their powers. Baldwin is watching them and wants them to be spellbound should they become unmanageable, but she doesn't want to repeat what her parents did to her. There's a theme of controlling parents throughout, and a suggestion that if you leave things be, children will make the right choices for them, eventually.

It just seems to lack purpose and the momentum isn't there. I knew Marcus would be OK because here's there to tell the tale. I enjoyed reading it but never felt I had to rush to get back to it. I didn't really know enough about either revolution to pick up on the historical characters, other than Monsieur Guillotin, but there are a few more to pick up on.