Series of apartment building flick past the train window. They're all numbered in a large complex. 5-12, 5-13, 5-14, a gap, 5-16, 5-17...
What happened to 5-15? 🤔
@NFG I blame my #Babylon5 rewatch for my first reaction being, "Gray 17 is Missing."
This is NFG's instance. There are many like it, but this one is mine.