After having therapy to save their marriage in the last series, Martin and Louisa face the challenge of living happily together with their baby James Henry. Meanwhile wedding bells are ringing for Portwenn's police constable, Joe Penhale and the Doc's nanny Janice Bone.

Martin is left holding the baby when Louisa has to take Year Six pupils sailing. He has to collect James from nursery every afternoon, but with surgery hours Martin is constantly late.