Josiah was a Human miner in the Orpheus Mining Colony on Luna.
In 2155, at Orpheus, he greeted Trip Tucker when Tucker and T'Pol were searching for their artificially produced child; Tucker introduced himself under the alias "Turner" (since he and T'Pol were operating covertly), but Josiah knew who he was. Josiah invited Tucker to a gathering of Terra Prime, to which the miner belonged – a ruse to capture Tucker and T'Pol, part of John Frederick Paxton's plan to expel all aliens from the Sol system. At the meeting, Josiah voiced anger over the increasing presence of aliens on Earth. At the end of the speech, he pointed out Tucker and revealed his true identity.
Another member of the group, Greaves, captured T'Pol, and they were taken hostage by members of Terra Prime. The mining facility was also a warp-capable starship, and it launched, with Tucker and T'Pol held captive on board, and flew to Mars. Josiah proceeded to assist Paxton with his plan to use the planet's verteron array to destroy Starfleet Command. As he was about to activate the firing controls, he was shot and presumably stunned by Archer. (ENT: "Demons", "Terra Prime")