Last week’s episode ended with a disturbing revelation – but one which made it even more clear why Ruth Wilson, who’s such an intense and powerful actress, agreed to star in this mystical mystery series. Playing her roles, she’s like a children’s poem: when she is good, she is very, very good. But when she is bad, she is… better. And now, as we all know, her Mrs. Coulter, who was pretending to be Lyra’s friend and protector, is very, very bad.