It's the beginning of the 20th century; the age of scientific progress.But for Venice the future looks bleak. A conference of scientists assembles to address the problems, among whose delegates are the parents of twelve-year-old Teodora.Within days of her arrival, she is subsumed into the secret life of Venice: a world in which salty-tongued mermaids run subversive printing presses, ghosts good and bad patrol the streets and librarians turn fluidly into cats.A battle against forces determined to destroy the city once and for all quickly ensues.Only Teo, the undrowned child who survived a tragic accident as a baby, can go 'between the linings' to subvert evil and restore order.