A Light in the Darkness, a Lock in the Door: Book 2 — Haiko Hornig

Henrietta Achilles, the heir of a legendary wizard, has a serious plumbing problem. When flooding from the wizard's house threatens to destroy everything around it, Henrietta must rally a group of unlikely allies to stop the deluge. Alongside Captain Booner's soldiers and Nate Flemming's motley bandits, Henrietta travels into the house's depths, a journey that brings danger...and discovery. Soon Henrietta encounters one of her uncle's lost creations—and he's a little suspicious about Henrietta winding up in charge. Meanwhile, secrets from Flemming and Booner's shared past explode into view, and the house's volatile magic threatens to sink the rescue mission... [A]n absolute delight. —Entertainment Weekly, for book 1 The action and wonder never stop in this intriguing sequel.—Kirkus Reviews