The Fog of Funeral Planet - S1.E66

As the 999 touched down on the Funeral Planet, its arrival (and whistle) disturbed a funeral procession, who decided to bury Maetel and Tetsuro alive as punishment, with the proper pomp and circumstance. They were rescued by Machiru, a woman responsible for ringing the funeral bell. She explained that the inhabitants on the planet were immortal, so killing for funerals became a past time when they witnessed one over 120 years ago, when a couple crash landed on the planet. The bell stopped ringing, and Machiru was killed by the procession as a result. Maetel and Tetsuro came across the procession and stunned them all. Maetel explained to Testuro that funerals would be given to them when they stopped moving, whether they were still alive or not.