There are some bright spots in the production : Dominic Cuskern gives a fine performance as William Cecil , Elizabeth 's adviser who campaigned for Mary 's execution as being essential to keeping England Protestant ; Richard Bourg as the Earl of Shrewsbury is touching in his appeals on Mary 's behalf ; Sean McNall is credible as the duplicitous Mortimer , who pledges fealty to both queens ; and Beth Dixon delivers a nice turn as Mary 's nurse . ''