Last March 10, the day he was fatally shot, Dr. Herman Tarnower was scheduled to have a small dinner party with a niece and his girlfriend, Lynne Tryforos. An anxious, angry Jean Harris phoned his home twice that day in a desperate attempt to see him.

Harris was st first "angry," then "worried," possibily in tears, according to Tarnower's housekeeper, who took the calls.

But the housekeeper, Suzanne Van der Vreken, acting on long-standing orders of the doctor, coolly brushed Harris off. First she said that the doctor was not home -- which was true. Then she lied about Tarnower's dinner plans.

"The first call, she [Harris] said, 'Is Hy there?' I said, 'No,' then she hung up," Van Der Vreken testified at the Harris murder trial today as a visibly upset, Harris glared. "The second call, she asked if Dr. Tarnower would be there for dinner. Since I follow his instructions I said no. She said, 'Is he going out?' I said yes. She said, 'Is he going to New York?' I said, 'I don't know.' She said 'If he's going down to New York, I could meet him there.' I said, 'I really don't know, Mrs. Harris.'"

Harris, 57, former headmistress of the Madeira School in McLean, Va., has been charged with second-degree murder in the shooting of Tarnower, author of the best-selling book on the Scarsdale diet, in the bedroom of his fashionable Westchester County home.

In his opening arguments, defense attorney Joel Aurnou tried to downplay stories of a love triangle as a motive for the killing, seeking instead to portray Harris as a depressed and insecure woman, frightened of aging and under pressure by her career. The actions that prompted Harris to drive to Tarnower's home the night of the killing had to do with events that had taken place in Harris' home in Virginia, he says.

Today's testimony in Westchester County Court here shed no light on those events. But it did -- counter to the defense position -- delineate an angry woman caught in a painful love triangle. Taking the stand for the second day, Van der Vreken drew a portrait of Harris as a woman who had long since become a nuisance to the doctor, a woman who did not know when it was time to go away.

The housekeeper also clarified testimony from the day before, confirming that Harris had said she would "sue" Tarnower and Tryforos -- not "shoot" as some courtroom observers had thought Van der Vreken said.

Speaking in her heavily accented voice, the Belgian-born housekeeper, who was clearly hostile to Harris and found enough of Tryforos to once have loaned her some hair rollers, said that Tarnower had spent the weekend before the shooting in his home with Tryforos. Harris, she said, called several times.

When she answered the phone, Van der Vreken testified, and Harris asked for Tarnower, the housekeeper responded that he was not there. When Assistant District Attorney George Bolen asked what happened in the event Tarnower was there, Van der Vreken sidestepped the question.

"If he was there, then he would answer the phone himself," she said smugly, after a pause.

Bolen pursued,asking what instructions, if any, Tarnower had left in case he was in.

"Dr. Tarnower told me that if Mrs. Harris called when he had guests for dinner I had to say he wasn't there," said Van der Vreken, adding that those instructions had been given "about six, seven months" before the shooting.

On the stand for most of the day, Van der Vreken described in detail the day of the shooting. She began with a picture of cozy domesticity, the doctor, arriving from the office office after five o'clock, settling into a small sitting room with his papers, his mood "the same as usual, content, happy." She said that Tarnower's guests -- his niece, Debblie Raizes, and Tryforos -- arrived for dinner about seven, in one car. Smiling slightly at the memory, Van der Vreken said that part of the evening's festivites had included a birthday cake.

"It was my birthday the day after, so Lynne Tryforos brought a cake -- which I didn't know -- and we all had a piece for my birthday," said Van der Vreken.

The guests, Van der Vreken continued, left at about eight. Tarnower took his usual medication, a "small laxative mixed with appleasuce" and retired, shutting off most of the lights, as he did when guests were not expected. Van der Vreken retired to her room to paint and watch television. Sometime later, she testified, she heard a buzzer sound. "I heard the buzzer -- I heard the buzzer once more, which was a surprise, the doctor had never done that before," said Van der Vreken. "I went into the kitchen, I heard the buzzer several times. I picked up the phone, I said, 'Doctor, what do you want?' -- he didn't answer the phone, but I heard a lot of yelling . . . there was Mrs. Harris' voice . . . I heard shots . . . I never heard Dr. Tarnower again."