The early Tom Baker era of the series is cited by Screenonline as the peak of "Doctor Who" in its first run. However, the BBC received several complaints from Mary Whitehouse of the National Viewers' and Listeners' Association that the series was unduly frightening for children and could traumatise them. The NVALA had been critical of the series before but the complaints reached their height in the Hinchcliffe period. Her strongest criticism was for "The Deadly Assassin", where an attempt is made to drown the Doctor at the end of an episode. While the BBC publicly defended the programme, after three seasons Hinchcliffe was moved onto the adult police thriller series "Target" in 1977, and his replacement Graham Williams, who had created "Target", was specifically instructed to lighten the tone of the storylines and reduce violence. Screenonline states that this resulted in "the start of an erratic decline in both popularity and quality" for "Doctor Who" which led to its eventual cancellation.