I drop underground on the hum of electric stairs, into the cool world of concrete and tile and Oz-like machines into one of which my coin now falls. Out spits my ticket to be thrust back into a plastic gate, whose part spring back to take me in as though I am Jonah and this is the whale. A whale with a 750-volt third-rail backbone.

Here comes the train, headlights boring out the dark, triggering pulses of light at my feet like a high score in pinball. It glides to a stop with a sigh, a whoosh and a contrary screech or two of brakes. Much light, clean, comfortable seats in which to sit and read the paper or stare out at the black into which we return.

This is really something, this Metro, smoothing my life, shooting me hard into mid-town in 11 minutes. Sometimes I do little calculations in my head. If you had $1.2 billion lying around, you could buy one Trident sub, or 3,427 subway cars. I can get to Silver Spring in 32 minutes. Dig a tunnel from a mile of Metro earth, throw in a station, and it will cost you $55 million. Go out to Utah and dig a subway of sorts -- the MX -- and it will cost you $55 billion. I can get to the Pentagon in a minute. Ding dong, the doors go catatonic. Sometimes when I fly through here I wonder who sits suspended overhead in a round-the-clock, fail-safe room deciphering the Persian Gulf through computer. Figuring Mideast permutations, making policy.

We go again, out of Pentagon, rising from earth to daylight. Monuments, bridges, pediments on one side, a hillside of ranked and lesser stones on the other. Here on this gray morning, heavy with summer. Arlington Cemetery. Doors open, doors close. No one ever gets on at Arlington Cemetery, except maybe a ghost or two. This is a stop for the subconscious.

We're out of there fast, reboring down under, ahead of a last glimpse of buildings shining on the horizon like Babylon. Babylon is Rosalyn, where people with briefcases scurry off the train and into the dimness. We let them walk into oblivion, for we are going places you wouldn't believe. We're going a hundred feet under the river, through sheer, solid, ear-popping rock -- through the long speed of darkness. To Foggy Bottom-GWU, where you see kids with nylon knapsacks.

Then to my stop. Ding dong. Farragut West. Where am I? Eleven minutes? Eleven hours? Subway lag. I ask a man next to me.What time is it? He presses his watch; digits appear on his wrist. Ding dong, the train is ready to go. Wait. Commotion behind me, a man in polyester and mustache is caught in the doors like a newborn between womb and world. He yanks at his pants trying to come free. He uses his briefcase as ballast. The moment freezes us, compresses us subway riders into one dimensional figures there on the surreal plane of the platform. I move toward the man, somebody yells. The driver pops his head back out, the expression on his face reading: "Oh." The doors let the man go.

Imagining a man being towed down the platform by a subway car, I make a call. The spokesman at Metro says: "If the door hits an obstruction, the brakes automatically lock and the driver has to recycle the doors before the train will move." In the beginning of Metro, the brakes locked if someone was just leaning against a door; that's been altered so the doors will tolerate an obstruction of an eighth of an inch or less, the spokesman says. There've been no serious incidents. "An envelope in the door won't keep the train from moving, but an arm or a leg certainly would."

Certainly, I say with relief.