If you've never been inside a sound stage, your first visit can be a little overwhelming, sort of like walking into L.A.'s new Union Station for the first time. These joints are huge.

The building's cavernous interior was mostly empty save for a small area at its center that was brilliantly lit by large carbon-arc spotlights-called Klieg lights-hanging from the maze of rafters and catwalks nearly three stories above the floor. As always, I felt a little nervous walking under those damned big lights. Some of them are more than three feet in diameter and heavy enough to put a good-sized dent in your fedora if the electricians didn't tighten the mounting bolts securely.

The area the Klieg lights were illuminating inside Sound Stage Fifteen was a set designed to replicate what looked to my eye like a parlor or drawing room straight out of the 1800s. Two actors I didn't recognize-a young fellow in chin whiskers that probably weren't his and a pretty blonde-were standing in the middle of the set listening to another fellow who was most likely giving them last-minute instructions on how to play the scene about to be shot. I guessed this because the guy was doing a lot of pointing and gesturing and because I recognized him as one of Warner Bros.' more colorful directors, Dmitriy Volodin, who is more commonly known around the lot as the Mad Russian despite the fact he hails from Poland.

The set was surrounded by the accoutrement of filmmaking: a camera mounted on a moveable, elevated pedestal; a boom extending out over the set to dangle a microphone above the actors' heads; and various and sundry lighting gadgets to supplement the overhead Klieg lights. All of this equipment, in turn, was surrounded by about twenty people. Most of them were crew members in work clothes, but there were also a few big shots watching the proceedings. The big shots were easily identified by their expensive custom-tailored suits.

I recognized one of the suit-types as Jack Warner. He spotted me, gave me a quick wave, and followed that gesture with an elevated index finger meaning he would be with me in a minute. Then Warner returned to the animated conversation he was having with two other suits. They didn't look pleased to be there.

On the set, Volodin finished his instructions to the actors and walked toward the camera, shouting in his high-pitched voice, "Quiet on the set! Quiet on the set! Get in your places! We are shooting this scene now!"

There was a brief flurry of activity as crew members took their positions, and then the big sound stage was suddenly quiet as a tomb. Volodin took a long look at the set, and apparently satisfied with what he saw, calmly said, "Camera . . . action."

I was standing at the side of the open-ended set, so I had a ringside view of the male actor as he emoted, "Caroline! What does this mean?"

The woman replied, "It quite simply means, Samuel, that I am going to have your baby."

Samuel, whoever the hell he was supposed to be, said something in response, but I missed it because a movement up in the sound stage rafters caught my eye. It was hard to see beyond the glare of the lights up there, but I thought I could make out one of the larger Klieg lights, an unlit one, swaying. For a brief moment I thought we were experiencing one of our famous earthquakes, but that didn't make sense because Klieg lights were supposed to be securely mounted; they shouldn't sway, even in an earthquake.

I looked harder and saw the misbehaving spotlight rise a couple of feet, then drop back down and jerk to a stop. Suddenly the meaning of what I was seeing became very clear. Somebody was up there in the rafters trying to unhang one of the hanging Klieg lights. The fact that the Klieg light in question was directly over the male actor's head made me think I ought to do something about the situation, and quickly.

As the light rose vertically again, I shouted, "Look out!" and launched myself across the set at the male actor. I hit him like a lineman tackling a quarterback-a very startled quarterback. He yelled, "What the hell?" and we landed in a heap on the set's carpeted concrete floor a little more than six feet from where he'd been standing a second earlier.

At that precise moment, the Klieg light crashed to the same floor only inches behind my outstretched legs. It sounded something like a garbage can full of broken glass being tossed out a third-story window. The crash was followed by shouts of alarm from the crew and a shrill shriek from the actress at whose feet we ended up.