2 Works by Joylee in Rivers of London - Ben Aaronovitch
The Folly takes on an unidentified body, well part of one anyway, and solves the mystery of the vanishing waterfoul along the River Lea. At the same time educating disbelieving colleagues and integrating new members to the team. All the while racing against the clock to make it on time to a Pre-school Christmas Pageant.
Nightingale might have been the last wizard, but he was never the last Issac. At least not from Molly's perspective. And now she has all these changes to deal with. She can hardly wait.