undefined behaviour

robotic voice announces
the stop we left was the last one on our roadmap
and now
we’re entering the uncharted territory

did I miss my last chance to get off
but I didn’t want to stop, didn’t like the last station
I want to move forward
but not continuously on the same train

I get up and press the telecom button
“greetings, when will the train stop?”
robotic voice responds “it’s undefined behavior”
what does it mean?
it means you may get different answers on each time you ask

when will the train stop?