How on earth did it happen, I used to wonder
that a whole city—arches, pillars, colonnades,
not to mention vehicles and animals—had all
one fine day gone under?
I mean, I said to myself, the world was small then.
Surely a great city must have been missed?
I miss our old city—
white pepper, white pudding, you and I meeting
under fanlights and low skies to go home in it. Maybe
what really happened is
The speaker dodges between the mythical past and the present. Having thought about Atlantis, she moves to the present and her own pang of nostalgia. The dash that ends the third line of the stanza forms a  caesura  or break, that marks the speaker’s transition from thoughts of Atlantis to her own personal nostaglia. 
 
 The relationship between the two time-scales and the two cities will be tied together elegantly later.
Atlantis— A Lost Sonnet