How does brinker get gene and finny to attend the mock trial?

Brinker Hadley decides to pay Gene a visit, and immediately starts accusing Gene of arranging Finny's accident in order to get a room to himself. Gene is naturally defensive, since the point hits close to the truth, and decides to distract Brinker by proposing they go down to the Butt Room in the basement to smoke. Once they are down there, Brinker proclaims Gene's guilt before everyone in the room, setting up a mock-trial kind of situation for Gene. The others in the room immediately start playing along, asking Gene questions about the "crime"; Gene jokingly participates, disguising his real guilt with a kind of far-fetched, sarcastic humor. He believes that none of them are actually suspicious of him after the incident, but the incident and Brinker's accusation still trouble Gene a great deal.