Set in an urban secondary school, Big School is a comedy about a dysfunctional staff room, unrequited love and interactive white boards. Chemistry teacher Mr. Church is hopelessly in love with the school's new French teacher, who in turn is being chased by a lothario gym teacher. David Walliams is 40-something chemistry teacher Mr Church, who has taught at Greybridge School for years. Catherine Tate plays the school's enthusiastic new recruit, Miss Postern, whilst Philip Glenister plays the lothario gym teacher Mr Gunn.