It was Van Horne's dying wish that his body be carried within a special funeral car attached to The Boundless. Crossing and re-crossing the continent on the rails he helped lay. Forever.
The funeral carriage is impregnable, welded together from plates of battleship steel, no windows, no doors. Inside is a mausoleum which contains the sarcophagus of Cornelius Van Horne -- and, rumour has it, other things of great value. When at rest in a station, a guard stands watch over the car. To make it even more inviolable, the exterior is electrified with a high voltage current. Anyone touching it would be electrocuted.  There is a key that turns the electricity on or off, and only the guard has one... And one other person aboard The Boundless....