Arthur Farrell reveals the dynamite in Phase 48.
Some time after the surviving Type-V mutants arrived in the former St. Louis, Arthur Farrell devised an audacious bluff to confront them, creating a number of sticks of paper dynamite to accomplish this.
Arthur Farrell used coloured paper to make the sticks of dummy dynamite. It looked realistic enough, suggesting that he modeled it on actual dynamite. He then strapped the sticks around his chest and under his jacket to pose as a suicide bomber.
It is implied that the residents of the Bradley Shelter became aware of the Type-V mutants after they arrived and set up camp in St. Louis. Based on John Farrell's prior experiences with Vilma Fachiri decades ago, Arthur knew that he could likely win her over, but would have to be very careful with the others, especially Victor Byron. He likely spied on their activities before devising his plan. On the day that he put it into action, he killed Morse with his bow and arrows before dragging the latter's body to the Type-V mutants' camp in the Millennium Hotel. When Jacco tried to draw his a pistol on him, Arthur stopped him by holding up a primed grenade and pulled back his jacket to reveal the dynamite, threatening to blow them all up. This stopped Jacco and earned Victor's immediate respect.
Following Haruka's death and Vilma's subsequent disappearance, Radha went to see Arthur and asked about the earlier use of the dynamite. The latter revealed however that the dynamite had all been fashioned out of paper. The two then had a laugh about this, but Arthur acknowledged that the ploy would not work again.