In shock scenes to air next Wednesday, disaster will strike after Jackson (Marc Silcock) and boyfriend Aaron Livesy (Danny Miller) head out for the night with Paddy Kirk (Dominic Brunt) and Marlon Dingle (Mark Charnock).
The foursome travel together in Jackson's van, but a tragic twist of fate sees the vehicle veer off the road, flip upside down and end up on some nearby train tracks.
Soon afterwards, the driver of an oncoming train spots the vehicle's bright lights ahead - but quickly realises that he has no time to avoid a devastating collision.
While Aaron, Jackson, Paddy and Marlon all get into the vehicle at the start of the evening, one will be left in jeopardy after the crash. However, details of whose life will be left on the line are being kept closely under wraps until transmission.
An Emmerdale spokesperson commented: "This is an incredibly dramatic episode and is the start of one of the most emotional stories we'll ever tell.
"In a tragic turn of events, it will bring together four of our most cherished characters for a gripping and poignant hour-long special which will leave viewers with their hearts in their mouths."
Emmerdale's shock train crash airs on Wednesday, October 6 at 7pm on ITV1.