Viewers may remember Jess the Cat from Postman Pat but now the black-and-white animal is the star of his own show. At the beginning of each episode, Jess comes across a big question that he investigates with help from viewers and his friends, which include Willow, a pony that acts as a wise motherly figure to the cat, and Billie, a mouse that carries a magnifying glass and binoculars to further investigate the question. Throughout their adventures, Jess and friends learn about the world around them.