Nov. 27 (UPI) -- PBS is teasing All Creatures Great and Small Season 4.
The network shared a preview of the season Monday featuring Nicholas Ralph and Rachel Shenton.
All Creatures Great and Small is based on the James Herriot book series. The show follows a trio of veterinary surgeons as they care for animals in the Yorkshire Dales.
Season 4 opens in 1940 as Winston Churchill takes office and Europe is under serious threat.
The new preview teases "love, friendship, family, and joy" as James (Ralph) and Helen (Shenton) consider starting a family. In addition, James and Siegfried (Samuel West) recruit a new assistant, Richard (James Anthony-Rose).
Anna Madeley, Patricia Hodge, Tony Pitts, Imogen Clawson, Paul Copley and Neve McIntosh also star.
"I can't wait for our Masterpiece audience to see this new season of All Creatures Great and Small. It continues to be full of the warmth and humor that has made it one of our most successful series ever," Masterpiece executive producer Susanne Simpson previously said.
All Creatures Great and Small airs on Masterpiece on PBS in the United States and Channel 5 in the United Kingdom. Season 4 will premiere Jan. 7 at 9 p.m. EST on Masterpiece.