Silverpilen

Origin
The Silverpilen started as a myth in Stockholm of a ghostly metro train. Painted silver instead of the customary green, the train has reportedly been sighted in abandoned tunnels and nearly empty subway tracks. Some claim those who step on may disappear entirely until the train resurfaces, sometimes weeks, months or years after the initial pick-up.

Effects
Seems to be attracted to disused and currently still subway tunnels and train stations. It will suddenly appear, run its distance and then just as suddenly disappear, searching for its next stop. It can be seen flickering between dim and dark shades, like a heartbeat or musical pattern. Anybody who boards the train will likely not reappear for a long time. Those that do are usually driven insane beyond reason or help.