The possibility of war is on everyone's mind with Helen preparing for the privations ahead and Tristan tasked to tape the windows in the event of bombing. Siegfried decides that they should conserve food and heating by eating their meals together, but Mrs. Hall takes his instructions to economize a bit too seriously. James treats Hamish, a sick dog who requires an operation and Tristan, who is tasked with overseeing his recovery, loses him. The vets forgo a posh evening out to treat a stray dog who has had an accident. Tristan is aghast at Siegfried's attempt to pair him with Deirdre Headingley, one of his crony's less-than-attractive daughters.

James treats Paul Cotterell's dog Theo, who has been losing weight and is diagnosed with Hodgkin's disease. James recommends that Theo be put down and Paul agrees. James doesn't realize the impact this has on Paul and the tragic results that ensue. James meets Lord Hulton, a hard working farm owner despite his aristocratic background. Hulton takes a liking to a horse that has wandered onto his property from the nearby military depot. At the Billings farm, James finds young calves who are wasting away. He thinks they have ingested an irritant of some kind, but the vets simply can't isolate it.