The Medium Beginning is the seventeenth chapter in Gunnerkrigg Court. It starts .
While Antimony is in physics class with Kat, Jones comes by and excuses Antimony to come study mediation under Jones' guidance. Jones finds out that Coyote asked Antimony to visit him in the forest and she tells Antimony that she should take Coyote up on the offer, as well as that "Coyote is no liar. Therein lies the danger." Antimony finds out that her mother was the last person from the Court allowed in the forest and that she was the last medium employed by the court. Jones uses this opportunity to anger Antimony in order to "assess her character."
The pair enter the training room where it is revealed that Jones and Eglamore had some sort of relationship in the past. While Parley is taking her sword-fighting lesson, Jones explains to Antimony that the Court took root in Gillitie Wood, but a schism arose because man wasn't content with ethereal explanations and became engrossed with technology. Mediums undertake negotiative roles during disputes between the technological and natural sides.
At this point Jones and Eglamore spar, and Jones flattens him quickly, even without a sword, as Eglamore expected "indoors and at close range." Jones seems to suffer a nick to the face and is able to grab the sword blade, but neither action leaves a mark, which surprises Antimony.
Andrew Smith appears during their fight, and afterward, Parley uses a deck of cards to demonstrate that his power is to "subconsciously create order where there was none," or in Parley's words "to make everything boring." Parley's dad, it turns out, was a certified psychic and the only person to officially complete the Eugene Gould Psychic Challenge, although Parley herself hasn't shown any sign of psychic ability yet.
While the three students and Jones are leaving the training room, Jones asks the students their thoughts on the meeting with Coyote in Chapter 14. Antimony seems to have the deepest insight. Jones explains that neither side is very understanding of the other. She then leads them to a meeting with Mort, and Antimony surprises the others by revealing that she befriended him on her own previously.