It is now spring 1939 and a potential world war looms. Tristan is now a qualified vet, while James enters a new stage of his life with Helen and at the practice. After being made joint business partner by Siegfried, James pushes to take on more responsibility via the Ministry of Agriculture's new bovine TB testing scheme, but its unexpected challenges risk pushing him to breaking point.

• James Herriot
• Colin Callender

• Drew Cain
• Susan Jameson
• Melanie Kilburn