The Earth Mail Ship

A spacecraft for mail, running the Limbo Galaxy on a set route with nobody aboard. Senders flag it down and load a conveyor belt, which is a lovely detail and exactly the sort of ordinary infrastructure this galaxy usually skips. Its moment comes when the Mob rob it of the Saviour Stone. An unattended ship on a published route carrying something valuable is a robbery waiting to be written, and the show waited until episode 32 to write it.