Del’s a little man with a big mouth. Whatever you’re talking about, he knows the subject better than you. Politics, stereo components, love advice, members of your family he’s never met, no matter; Del will disabuse you of your faulty notions. Every bar has its Mr. Dooley, its Cliff Clavin. Del’s ours at the Albatross.

He’s in his happy place holding forth. He’ll tell you how, despite their giant eyes, owls are among the least intelligent of avian species and how the fearsome locust of biblical plague are nothing but the humble common grasshopper and how the great song composer Cole Porter took his name from the French word colporteur, which is a peddler of biblical literature. There’s nothing he doesn’t know everything about.

On days Del’s at the bar he arrives hours before my shift. He’s a lightweight so I know he’s well into his cups by the time I take over. Today he’s buttonholed a young man I don’t recognize. He’s haranguing the poor man about the election, inches from the man’s chest, spittle flying. From time to time the guy looks around the room, over and around Del’s balding pate, which barely comes to his own chin, looking for rescue or reprieve. But none will come. Because the regulars know when Del has fastened his grip this way there will be no mercy. The only chance is to run for the door when Del goes to empty his bowels, which the young man does, not even bothering to finish his drink.

Del’s gone about ten minutes. I go to the men’s room to check on him and he’s standing in the middle of the room, pants around his ankles, staring at the wall. I help him with his pants and position him in front of the sink, then return to the barroom.

He returns eventually. Looking around, as if he’s misplaced something, he scans the room for a familiar face, someone to talk at.

One time I sat next to him and made the mistake of revealing the model of computer I had. An hourlong lecture followed, punctuated by Del calling me a fool. I took my drink and moved to the other end of the bar. I learned my lesson. Now, whenever he asks me anything I agree with him. It cuts him off at the knees. He can’t debate or argue, which is what he lives for. Drives him batshit. Or I play dumb. Yesterday he asked me who I planned to vote for.

—Is there an election coming up? I ask.

I cut him off. He looks dumbfounded but doesn’t argue for once. Takes forever gathering his things to go. He lingers by the door talking to Eber, who always indulges him, no matter how long-winded he gets. Eber’s getting paid by the hour, so maybe listening to Del’s raving beats looking out at the deserted street. He tries to talk Del out of riding his bike home. Offers to pay for a car. Del insists he’s fine.

Next morning I see him at the coffee shop. A jagged stream of dried blood snakes from the left side of his forehead down his cheek, coming to a stop three-quarters way down his shirt. He says he took a spill riding home but has no memory of how, nor of standing lost with his pants down in the bathroom at the bar. He apologizes if he caused any trouble. Says I should always tell him if he’s out of line. Then asks what music I’m listening to on my headphones. It’s an old trap. I say goodbye and walk away.

—I wrote a review of Luc Sante’s new book