Mike: Where's Vyvyan?
Rik: Well, he said he was going inside to water his plant. Strange that such a ruthless and sadistic maniac as Vyvyan should care for a begonia. Must have had it two years now.
Mike: And it was dead when he got it.
Rik: Yes... Still, give him his credit - he's watered it every day!
Mike: Only because he can't be bothered to go upstairs to the lavatory.
It's obvious that they just walked into the train station and started filming, because all throughout the sequence people are staring at them.