A Long Journey
Although his stomach was more efficient than an incinerator and could squeeze out all the energy from ordinary nutrients, the Myrtharians' energy of choice was still minerals, a few metals, along with heat and radiation. It had taken Jake quite a while to come up with a suitable replacement power source, but he had finally succeeded.
That little gravel that looked vaguely like a brownish pellet was military-grade plutonium-239, an artificial radioactive atom derived from uranium-238 in nuclear power plants. At his request, Will had gone to great lengths to get his hands on this prized commodity.
Back then, when Earth still existed, getting your hands on plutonium would have been impossible without special authorization. On B842 it was different. There were more valuable sources of energy than radioactivity and any material, as long as it was ordinary, could be easily obtained through the Oracle Store.