Last week I went to the Mercury Lounge on Houston Street to see Mark Eitzel play a solo show. Although I’d been in the crowd at a bunch of his New York-area gigs in the mid-to-late ’90s, I hadn’t seen him live in about 15 years, and I’d forgotten how much I adore his songs and his voice. Great as it was to be reminded of this, the night was in the end a strange one, capped by the most unsettling sequence of events I’ve witnessed in 30 years of concertgoing.

Mark Eitzel. Photo courtesy of Merge Records.

More on that in a moment. First, Eitzel himself. If you don’t know his work, do go make yourself familiar with at least some of it. He recorded several marvelous albums with the band American Music Club—1991’s Everclear is a good place to start—before embarking on a solo career highlighted by 1996’s 60 Watt Silver Lining and 2001’s The Invisible Man. He is a songwriter of rare beauty, a singer of often frightening intensity, and a true poet of American failure. I’ll admit this last bit is a simplification, which runs the risk of typecasting him as an unremitting sad sack when there are many more dimensions to his art than that. But plain facts can’t be ignored. There’s a lot of darkness in his songs, a lot of depression, a lot of obsessive-compulsive behavior, and a whole lot of alcohol.

There was one other thing I’d forgotten about Eitzel: that he can be mercurial, bordering on bipolar, in performance. I was reminded of this, though, pretty much as soon as his set began. One could not call him comfortable onstage. Sometimes it looks like he’s trying to wriggle out of his own skin while singing. He’s notorious for starting songs, then stopping them prematurely; engaging in bizarre, hostility-laced banter with the audience; and announcing, “This is my last song,” when he’s only played two or three. He did all these things at the Mercury, and not having a backing band to negotiate with further enabled his seemingly innate flightiness. But then he’d step away from the microphone, as he did on a touching new song called “Go Where the Love Is,” and let out a passionate, full-throated bellow that pierced us all to the core.

As the moments of transcendence passed in awkward alternation with the bouts of self-loathing, I found myself silently rooting for Eitzel to pull through, stick with the music, blow the demons away once and for all. I’ve met the man before; I interviewed him, almost 20 years ago now, in the company of R.E.M.’s Peter Buck, with whom he was collaborating at the time (and a memorable chat it was, in the Polynesian-themed Tonga Room of San Francisco’s Fairmont Hotel, where a fake monsoon happens every 15 minutes). But I certainly can’t say I know him. Even so, the longer the set wore on, the more protective of him I felt.

It became clear after a while that at least some of Eitzel’s discomfort was being triggered by the actions of a person in the audience. A little more than halfway through the show, he stopped playing his acoustic guitar, turned slightly to his left, and said, “Could you please stop doing that?” The question, sharp but not impolite, was directed at a rather mousy-looking Asian man who I’d guess was in his early thirties, standing near the right corner of the stage by a small set of stairs. Apparently, he’d been taking photos. The man quickly, with some embarrassment, obliged Eitzel’s request and put his camera down. Eitzel went back to playing, but through the remainder of the set he’d keep throwing fierce glares to the left, as if he just couldn’t get over the affront.

The real last song of the evening was “Everything Is Beautiful,” the gripping closer of 60 Watt Silver Lining. It’s a far less cheery number than its title would suggest. “Everything is beautiful,” Eitzel hisses in the chorus, “but babe, not you or me.” On this night, the song was not destined to be completed. About a verse and a half had gone by when a loud series of thumps echoed through the room. They came from the right corner of the stage. The same mousy-looking Asian man who’d been yelled at earlier by Eitzel was now lying unconscious on the floor of the club. With no warning, he’d fallen straight down, his head ricocheting sickeningly between the steps of the staircase leading to the stage. The bright red gash by his right ear nearly matched the color of the Converse All-Stars on his feet.

Looking stunned, Eitzel instantly put down his guitar and rushed to the edge of the stage, but no farther. In the confusion, a crowd gathered around the fallen man. One of the women standing closest to him kneeled down and took his pulse. Another pulled out her phone and called 911. As she was giving the club’s address to the operator, the man regained consciousness. He was able to speak and told the woman his name, though too softly for me to hear. Dazed and even more embarrassed than he’d been before, the man was soon helped up by two security guards, who slowly escorted him out of the room and through the service exit to the street.

I spoke with the music room bartender and a couple of other people who’d been standing nearby. They told me that the Asian man had had at least one drink but showed no signs of being intoxicated. After getting singled out by Eitzel, though, he’d become visibly nervous, and every new glance from the stage had added to his distress. The tension got so great that he finally snapped—fainting, so it seemed, out of pure shame.

By the time the hubbub ended, Eitzel had packed his guitar back into its case and was preparing to leave the club. Realizing what was going on, the crowd turned back to the stage and warmly applauded. The message in that applause was both encouraging and pleading: Don’t leave us this way. Finish the last song, or play something else. Eitzel just shook his head. No. One man’s darkness had collided with another’s, and an encore was unthinkable. Without a word, eyes haunted, he grabbed his guitar and walked out the door, onto the same street where an ambulance had just retrieved the man who’d collapsed in front of him.

I hope they’re both okay.

Update 6/2/16: Well, I can’t vouch for Eitzel, but I can tell you that the man who fell—a photographer named Mike—is just fine. I know this because he got in touch with me recently, to inform me that he was indeed all right and to correct some inaccuracies in my reporting. I’ve made those corrections in the text above and, with his permission, I’m posting his own account of what happened here.