“I talked to him once,” Dennis said, looking off the roof, toward Up Campus, where some students were staging a protest about the tuition hike that was about to come into effect. The protesters walked slowly across the viaduct, their signs bobbing in the air above them. “Maybe twice. We just talked about Polly. About the class. It was nothing. Look, if you two think that I may have had something to do with Williams skipping town-”

“It’s not that,” Mary said sharply. “It’s just that there are other things. Things you don’t know about yet.”

“What other things, Mary?”

Brian produced the book. He showed it to Dennis carefully, as if it contained a terrible secret. Brian flipped through the book, pausing on some of the pages as if a story could be told in the nonsense language.

“What the hell is it?” Dennis asked.

“It’s Williams’s book about the girl, Deanna. The girl from Cale that detective talked about.”

“Except it’s not a book,” Dennis said flatly, as if he was still trying to grasp the concept of the two words-for the for the for the for the for the-on those pages.

“Right,” Brian put in. “This is why I believe-we believe-that this is all part of some kind of…ploy on Williams’s part.” Brian explained it all to Dennis: uncovering the detective, Brian’s trip to Cale High and his discussion with Bethany Cavendish, the cryptic phrase Mary had seen on that typed page in Williams’s office, Della Williams’s note to Mary on the night of the party, and finally his and Mary’s e-mails to Troy Hardings.

“Shit,” whispered Dennis. He opened the Weber and transferred the hot dogs to a plastic plate. For a few moments he was silent, contemplating what he had heard. “So you think Williams had something to do with this girl in Cale?”

It was the first time anyone had expressed it in words. Yet it had been there, unspoken between Brian and Mary, from the moment he had showed up at Brown late two nights before. Bethany Cavendish had told Brian, It was as if he was there. An innocuous admonition at the time, but now, looking back with all the information they had gathered in the last day, it carried an undeniable weight.

“I think so,” Brian said.

The knowledge of what they were involved with now fell on them, and they stood silently on the hot roof of the Tau house, contemplating their roles in what was happening.

“What do we do?” Dennis asked. His brothers were at the door asking for the food, and he passed the plate inside.

Brian and Mary had already spoken about it on the way to the Tau house. They had decided that there was no other way around it, that if they wanted this thing to stop they had to go the whole way, and to do that they must get to the root of it. They must find a missing girl, again, for a second time, and then Williams’s role might be revealed. Mary had already resigned herself to the fact that she would not be going home this weekend to study as she had promised; in fact, she had already called and told her mother. When her mom asked if Dennis was somehow involved in Mary’s decision to stay at school, Mary had neither confirmed or denied it.

“We have to find her,” she told Dennis now, referring for the first time not to Polly but to Deanna Ward.

That night, he met Elizabeth at the Cossack, a little bar on the border of DeLane and Cale. She was already drunk. He slid across from her and she looked at him, her glare unfocused, sloppy. “What’s wrong with you?” he asked. They had been talking again in the library, and while Dennis had to admit it wasn’t like before, there was still a certain charge to it. She was at least acknowledging him again, looking at him and considering his thoughts.

“Nothing,” she slurred. “This-this damned dissertation.” The word was dirty on her tongue, a swear.

“So, I’m going to be busy these next few days,” he told her.

She only nodded heavily.

“I’m going with some friends of mine on a trip,” he said.

Again, that slow nod. She knew all of this, of course, but he was making sure. Making sure she knew so that she would remember when he returned, so that maybe-maybe that old energy would return. Who knew: maybe that would be his reward. In just a week, he had gone from angry at her-the kind of anger that is unhealthy, vile-to something else. Something like desperation. Yes, he admitted it: he was desperate for Elizabeth now that she had turned him away. Dennis stayed awake at night thinking of ways to bring her back.

They were silent for a moment. And then she said, “I got a tattoo.” When Dennis didn’t say anything, she continued, “Want to see?”

He stared at her as she tore back a square of gauze and showed him the back of her hand. “Isn’t it cool? You ever seen anything like that?”

“No,” he lied. “No I haven’t.”

In the blood-dotted ink he saw an S and a P, entangled.

They had planned the Cale trip for Saturday, but it turned out that Dennis had a mandatory charity event with the Taus, so they postponed it until early the next week. Brian and Mary spent the weekend sitting in her room at Brown, anxiously waiting on a call from Dennis. They played Uno, their hands moistening the deck until it was so slick that it could not be shuffled. They watched reruns of Seinfeld and Friends and Mary’s entire DVD collection: Persuasion, Elizabeth, Mel Gibson’s Hamlet. They listened to Mary’s CDs, falling asleep here and there to the Weepies and Cat Power and the Arcade Fire. They spoke to each other in short, clipped phrases about anything not related to Deanna Ward.

On Sunday afternoon, Mary checked her mail at the campus post office and found a crude package in the box. It was a mangled manila envelope that had been taped and lined with a series of months-old Attn’s on the outside. Her name was the last in the line: M. Butler.

Mary waited until she returned to Brown Hall to open it. Inside, she found a VHS tape. Someone had written on the white strip in the middle of the tape, This might help.

She pulled out her old VCR from under the bed and plugged it in. She and Brian sat in front of the television and waited for an image to appear. The film was grainy. Lines ran through the wavering picture, making it difficult to see what was happening.

But Mary had seen this film once before. It had been freshman year, in Dr. Wade’s Psychology 101: The Milgram Experiments.

The experimenter was asking the subject a question. This man, Mary knew, was being paid by Milgram to scream when the participant pushed the buttons on the “shock generator.” When the subject answered a question incorrectly, the participant said, “You will now get a shock of one hundred and five volts,” and he pushed a button on the machine. The subject in the next room cried out in mock pain. The participant said, “Just how far can you go on this thing?”

The scientist, who was also one of Milgram’s actors, said, “As far as is necessary.”

The participant said, “What do you mean ‘as far as is necessary’?”

“To complete the test,” the scientist said.

The participant continued. The next time the subject answered incorrectly, the participant pushed a button and said, “One hundred and fifty volts.”

Again, the subject cried out. “Get me out of here!” the man shouted. “I told you I have heart problems. My heart’s starting to bother me now.”