The Vhnori death ritual developed amidst the presence of many naturally occurring subspace vacuoles on the Vhnori homeworld. They originally placed the bodies of the dead into these vacuoles believing that this would transport them to the Vhnori afterlife, called the Next Emanation.
Unknown to the Vhnori, the vacuoles actually led to a planet in the Delta Quadrant. On this planet the bodies of their dead had been piling up for thousands of years, resulting in the only known concentration of the 247th element known to the Federation.
He returned using one of the cenotaphs having seriously disturbed the Vhnori's faith. However, it was discovered that an unusual amount of neural energy existed in the planet's rings, perhaps implying that the Vhnori afterlife may not be completely without foundation. (VOY: "Emanations")