The Metro

Iron In The Soul p.91
'The city is hollow' - thought Daniel. He was conscious, beneath his feet, of the caverns of the Underground; in front, behind, above, of tall cliffs pierced with openings.

The Age Of Reason, p.27
.. even when he was alone, in the metro, people looked at him rather quizzically.

The Age Of Reason, p.137
Boris, on his way past, looked appreciatively at the dyeing shop, and then plunged into the blonde, fastidious silence of the street. Street, indeed! It was no more than a burrow with houses on each side. 'Yes, but the Metro passes underneath it,' thought Boris, and he drew some comfort from this notion, conceiving himself for a minute or two as walking on a thin crust of bitumen, which might perhaps crack.