Goof: There is a very obvious continuity error near the beginning of the episode. As Jonathan leaves Maddy's flat and sets off downstairs, he is wearing his duffel coat. A second later, as we see him walking downstairs from a different angle, his coat is slung over his shoulder.
Phillipa [ describing her 'channelling' capabilities ]: It's like someone whispering inside a huge cave. And that's when I can feel him enter inside me.
Phillipa: Sargor. Although he's from the constellation of Taurus, of course he speaks to me in English.
Maddy: Well it's always good to have a second language.
Maddy [ worrying about a possible interrogation ]: What if they inject a truth drug into me?
Jonathan: It wouldn't stand a chance.
Jonathan: Chung Ling Soo – real name William Robinson
Jonathan is referring to the American stage magician William Ellsworth Robinson (1861 – 1918). He changed his name for a touch of exoticism and pretended to be Chinese, never speaking on stage and using an interpreter where necessary. He was famous for his bullet-catching trick, where marked bullets would be shot at him and he would supposedly catch them in his hands or teeth. In fact he palmed the bullets. However, the trick would prove his undoing. On March 23 1918, he performed the trick, but the bullet that was put in the gun failed to drop into the chamber below because the gun had not been cleaned. He was shot in the chest and died the next day. There are theories that the death may not have been accidental, but nothing has ever been proven.
Jonathan: This would be your Roswell.
He is referring to the famous/infamous UFO sighting in 1947 at Roswell, New Mexico. Supposedly a space ship crashed nearby and there was a military cover up to hide the truth. There were even rumours of an alien autopsy. Given the subject of this episode, the allusion seems entirely fitting.