Film crews for the programme have been shooting at the Nene Valley Railway over the past few days, although exact details of the storyline in question are currently being kept under wraps.
Speaking to Peterborough's Evening Telegraph newspaper, series producer Oliver Kent commented: "It was a shoot involving a couple of teenagers and a train - and it being Casualty, it is safe to say that it doesn't go well.
"This is a big spectacular storyline we have been building up to."
He added: "Nene Valley is the best spot for this, as there are not many locations where you can film so close to the tracks. We filmed here a few years ago, so we know it very well."
Filming for the stunt was expected to wrap yesterday, while the episode is due to air in June.
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