On a map, it is a vital artery for millions of commuters transferring from one subway line to another, a means of moving someone from deep in Queens to his job almost anywhere else in the city. But it is also, in person, just a tunnel, a particularly joyless and grim passageway even by New York City subway standards, wrapped by the sprawling Times Square station above and below. It is almost completely lacking in personality and identity; the police who patrol the station, when referring to the tunnel, call it “the tunnel.”

On Monday, this humble passage became the scene of a would-be suicide bomber’s attempted terror attack. It would seem an unlikely target and the very opposite of a high-profile, symbolic location in a city filled with them.

A visit to the tunnel as a destination, seeking clues to a motive, turned up the novelties within.

The tunnel, or an early version of it, opened in 1932, when the subway fare was 5 cents. “600-Foot Pedestrian Tunnel, Linking Subways, Opens Today,” an article in The New York Times announced, its writer dutifully describing the attributes of a tunnel: “The passageway is so constructed that it will be possible for pedestrians to make their way from the west side of Eighth Avenue to the east side of Broadway without coming to the surface.”