Black T - Shirts is back with a bang. Sir Martin Sorrell, a titan of the advertising world, joins us for an unmissable episode. From his early career at Saatchi & Saatchi to founding WPP, to exploring the future of advertising with the Monks, Sir Martin has shaped the industry in ways few others have. Adam tries to sell Thinkerbell, and then we put S4 to the ultimate challenge: the Pub Test.