Billie Piper at the premiere of her film Scoop last yearBillie Piper has spoken for the first time about her unexpected appearance in the recent Doctor Who finale.At the end of May, the Bafta nominee surprised many Whovians when she made an unexpected appearance in the season finale’s final moments, which saw Ncuti Gatwa’s Time Lord regenerating into a mysterious character played by Billie.While some took this to mean that the former pop star was the newly-unveiled Sixteenth Doctor, others were less convinced, pointing out that some hallmarks of a new Time Lord being revealed had not been present.