The very end of White Teeth is really more a continuation of the story. Or, if we think back to the epigraph, it's a prologue for the future. This story doesn't so much end as it does stop.
The very last thing that happens is that the FutureMouse runs away while Archie, who is pleased to see it escaping, thinks: "Go on my son!" (20.146). Go on, huh? See what we mean about this not being the end of the story?