Get them to the church on time! The wedding of Yorkshire Dales veterinarian James Herriot (Nicholas Ralph) and farmer’s daughter Helen Alderson (Rachel Shenton) opens Season 3 of the delightfully poignant PBS drama All Creatures Great and Small, adapted from the popular books and now set in 1939. Before the “I dos,” though, there are cows to test for tuberculosis, nerves to overcome and a wedding ring to locate. “I was reading the script and smiling cheek to cheek,” Ralph says. “It was touching, romantic. There was drama, but it was also very funny.” James and Helen’s nuptials kick off another seven-episode season of the Masterpiece favorite, which was filmed on location in Yorkshire, England, from March to July of 2022. The wedding, Ralph reports, was shot at two separate churches — one for the interior, another for the exterior — and a pair of special guests were on set for the occasion:...