IT WAS A LONG day in Judge Michael Horton’s courtroom that has felt more like a long night, meaning the night the Carsons died.

Katherine Welsh has artfully put the cops on the stand and then led them and the computer expert through the events of that bloody night, in the same artful way she keeps bringing the whole thing back to Rob Jacobson’s DNA every chance she gets.

It finally reached the point where I thought that if these three words—“the defendant’s DNA”—were the trigger for a drinking game, we’d all leave Judge Horton’s courtroom drunker than St. Patrick’s Day.

I offered as many objections as I could along the way, especially during the animated video, trying to slow her roll, but realized the entire time that my client and I were the ones getting rolled today, something I warned him in advance was about to happen.

In normal circumstances, my only immediate goal once this day in court had mercifully ended at five o’clock would be getting home, getting in a long beach walk with Rip no matter what the hour, followed by an even longer hot bath, followed by rice and beans from Fondita that I’ve been saving as comfort food.

But these are certainly not normal circumstances, which is why instead of being back in my own home, I’m in Claire Jacobson’s, in the living room of the big house in Sagaponack, uninvited and unannounced, after her husband told me she is back in town, listening to her explain to me, chapter and verse, why she wants to testify in her husband’s defense, even though she’ll be called to the stand by Katherine Welsh and not me.

“Let me help you,” she says.

“No,” I say.

I tell her I’d use stronger language, but that I’m a lady.

“Since when?” Claire Jacobson asks.

She is dressed as if on her way out to dinner, and not just for rice and beans from Fondita:

Black minidress with three-quarter sleeves that I am almost positive I eyeballed recently at Giorgio Armani in the city. Low heels the same color as the dress. Pearls. Her hair looks freshly done.

No wedding ring.

“I don’t mean to sound presumptuous,” I tell her, “but are you heading out on a date?”

“Of course you mean to sound presumptuous,” she says. “It’s kind of your thing, isn’t it? Or at least one of them.”

“You haven’t returned any of my calls,” I say.

“Kind of my thing,” she says. “Not returning your calls. And as for your question: It’s none of your goddamn business where I’ve been.”

I’m seated on the couch. She’s still standing and pacing, occasionally checking the phone in her hand.

“I am going out, as a matter of fact,” she says. “Not that that is any of your goddamn business.”

“I need to know why you are willing to waive spousal privilege and testify for the prosecution,” I say.

“Because despite everything, I still love my husband,” she says, “and have never believed he is capable of murder. I believe I can convince the jury of that.”

“Or,” I say, “you’re as good a liar as he is and since you can’t murder him for the way he’s humiliated you, you want to get on the stand and do everything possible to bury the sonofabitch.”

She doesn’t so much smile as bare her teeth. “I guess you’ll just have to wait to find out, won’t you?”

“Don’t do this, Claire,” I say. “Because if Katherine Welsh gets you on the stand, the one who’s going to get buried is you. Trust me.”

“See, that’s the thing,” she says. “I’m asking you to trust me .”

I shake my head. “You need to sit this out,” I tell her. “By not sitting in that chair. You need to call Welsh and tell her that you’ve changed your mind on spousal privilege. Once you do, she can’t compel you to testify.”

“You don’t understand,” she says. “I’m the one who went to her.”

I touch a finger to my ear, as if I hadn’t heard her correctly.

“You,” I say. “Went to her.”

“I thought it would be more powerful if I were her witness, and not yours,” she says. “It’s brilliant, actually.”

“Yeah,” I say, “if it’s an episode of Law & Order. But it’s not.”

“I’m doing this.”

“What you’re doing is walking into a trap.”

She shakes her head now. “I know what I’m doing,” she says. “Now please go. I really do have plans, and my dinner companion will be arriving soon. And please note, for the record, that I said companion, and not date.”

“Claire,” I say. “I couldn’t begin to unpack your relationship with your husband. Or his with you. I have more than enough trouble understanding my own relationship with him. But you cannot do this. Can not. Whether you sincerely want to help him or not.”

“For the last time,” she says. “Trust me.”

“You know who I trust?” I say. “Me.”

“You don’t know what I’m going to tell her.”

“Okay,” I say. “You got me. What are you going to tell her?”

“That I was with Rob the night of those murders,” she says.