She moved jerkily, and refused to be seated when Robb asked her. Her hands were clenched and shaking. She seemed not to blink but to stare fixedly, as though her attention was only partly here.

Robb looked at Monk desperately, then, as Monk said nothing, he began to question her.

She replied in a voice that was unnaturally calm that she knew nothing at all. She had taken dinner in her room and had not left it except to go to the bathroom. She had seen no one other than the servant who had ministered to her personal needs. She had no idea what had happened. She had never quarreled with Mrs. Stourbridge ... or with anyone else. She refused to say anything further.

And no matter how either Robb or Monk pressed her, she did not yield a word. She walked away stiffly, swaying a little, as if she might lose her balance.

"Did she do it?" Robb asked as soon as the door was closed.

"I have no idea," Monk confessed. He hated the thought, but she appeared to be in a state of suppressed hysteria, almost as if she moved in a trance, a world of her own connected only here and there with reality. He judged that if there was one more pressure, however slight, she would lose control completely.

Was that what had happened? Had she, for some reason or other, gone to see Mrs. Stourbridge in her bedroom, and something, however innocently or well meant, had precipitated an emotional descent into insanity? Had Verona Stourbridge made some remark about Cleo Anderson, suggesting Miriam leave the past and its griefs behind, and Miriam had reacted by releasing all the terror and violence inside her in one fearful blow?

But where had the croquet mallet come from? One did not keep such things in a bedroom. Whoever had killed Verona Stourbridge had brought it, and it could only be as a weapon.

The murder was premeditated. He said as much aloud.

"I know," Robb admitted. "I know. But she still seems the most likely one. We’ll have to go farther back than I thought. I’ll start again with the servants. It’s here, whatever it is, the reason, the jealousy or the fear, or the rage. It’s in this house. It has to be."

They worked all night, asking, probing, going back over detail after detail. They were so tired the whole house seemed to be a maze going around and around itself, like a symbol of the confusion within. Monk’s throat was dry, and he felt as if there were sand in his eyes. The cook brought them a tray of tea at three o’clock in the morning, and another at a quarter to five, this time with roast beef sandwiches.

They again questioned Mrs. Stourbridge’s maid. The woman looked exhausted and terrified, but she spoke quite coherently.

"I don’t know nothing to her discredit, not really," she said when Robb asked her about Miriam. "She’s always bin very civil, far as I know."