When Susan Vance, a scatterbrained young woman, takes a shine to Dr. David Huxley, a sober palaeontologist, mayhem ensues. Dr. Huxley, engaged to be married and intensely interested in the arrival of the brontosaurus bone required to complete his project at the museum, is inextricably bound up with Susan’s escapades when she finds herself responsible for Baby, a tame leopard shipped to her New York apartment and intended for Susan’s aunt in Connecticut. The plot thickens when George the Terrier steals the priceless bone and buries it, Baby escapes, and an untamed leopard escapes from a circus convoy (resulting in a twist on the mistaken identity ploy). Will Susan’s love for David be reciprocated? Will David get his bone back? Will Baby be brought up — or brought down?