The Underground Man

complete disclosure to the police.”

Taylor stared at him. “Are you serious?”

“Absolutely,” Steve said. “At least within the confines of the hypothetical situation Tracy’s set up.

“O.K., Tracy. It’s your party. What if Jack Walsh turns up dead?”

Tracy frowned. “Now that I think about it, it’s not so perfect after all.”

“Oh no? Why?”

“Because the relatives all came together.”

“What difference does that make?”

“Well,” Tracy said. “In a book they’d all come separately. And they’d go in and out without meeting each other. In fact, none of them would even know the others had appointments. Of course, that couldn’t happen in this case with them all living in the same house. Jack Walsh calls one, he gets ‘em all. So they all know they all have appointments, they all come together, and they discuss everything before each one goes up and after they come down.”

“Why does that make a difference?” Steve said.

“Because if they all came separately and there was no communication among ‘em, no one would know who did it. Or rather, who didn’t do it.”

Taylor frowned. “You’ll forgive me if I’m not following this?”

“I think I am,” Steve said. “But why don’t you spell it out.”

“O.K.,” Tracy said. “They’re all together. They’re all going up and coming down one at a time. There’s six of ‘em, right? O.K. Say the fourth person goes up and finds him dead. Well, then he knows the killer’s one of the first three who already went up. And he knows the killer isn’t one of the last two who haven’t gone up yet.”

“And he know it isn’t himself,” Taylor said.

“I’m serious, Mark,” Tracy said. She turned to Steve. “You see what I mean?”

“Yeah, I do,” Steve said. “But there’s another consideration. That fourth person-you got your notes there, Mark? Who was the fourth person? In fact, give me the order again.”

“O.K.,” Taylor said. “Jason Tindel, Fred Grayson, Rose Tindel, Pat Grayson-she’s number four. Then there’s Claire Chesterton, and Carl Jenson.”

“O.K.,” Steve said. “Take your example. Pat Grayson goes up and finds him dead. She knows Jason Tindel, Fred Grayson, or Rose Tindel did it. She also knows Claire Chesterton and Carl Jenson didn’t.”

“Seems a shame to wash out Jenson,” Taylor said.

“If that were the case,” Steve said. “She obviously didn’t tell anyone.”

“Why is that?”

“Because Claire Chesterton and Carl Jenson still went up.”

“Wait a minute,” Taylor said. “Why wouldn’t she tell?”

“Because she’s afraid they might think that she did it,” Tracy said excitedly.

“Oh, come on,” Taylor said.

“No, good enough,” Steve said. “That’s a motive for her, and that’s a motive for all the others. Take that as a premise. Whoever finds him dead won’t admit it. He’ll lie to the others and claim they met with him and he was just fine.”

“So what does that accomplish?” Taylor said. “She comes down, she doesn’t tell the others he’s dead. Big deal. The next person up is gonna know.”

“Right,” Steve said. “But only that one person. And that’s what makes the whole thing so interesting. It’s like one of those old logic problems. In fact it’s a paradox.”

“What?” Taylor said.

“I’m not following this,” Tracy said. “What’s the paradox?”

“It’s a nobody-could-have-killed-him paradox.”

“A what?”

“Look. Here’s the setup. Jack Walsh is found dead. One of the six must have killed him. Now we must assume all six will operate by the same rules. That is, if a person finds him dead, they won’t admit it, they’ll pretend he’s still alive. And we also must assume that the murderer doesn’t want to be known. In other words, the murderer won’t kill him if any other person would know for sure that he did it.

“O.K., that’s the setup. If Jack Walsh is found dead, which one of them could have done it?”

Mark Taylor stared at him. “How the hell should I know?”

“All right, Mark. Let’s make it easier. Which one of them couldn’t have done it? Logically, I mean.”

“Steve,” Taylor said. “I took Math 101 for football players. I got a gentleman’s C. This is out of my line.”

“All right. Tracy-you know who couldn’t have done it?”

“Sure.”

“Who?”

“Jason Tindel, of course.”

“Right. Why?”

“Because he came first. Jason Tindel called on him first. If he killed him, when Fred Grayson went up and found him dead, Fred would know Jason was the murderer.”

“Right,” Steve said. “And one of our rules is the murderer won’t do it if anyone would know it was him. You follow that, Mark?”

“Right. If Jason did it, Fred would know. So it wasn’t Jason. I’m with you there.”

“Fine,” Steve said. “Now consider Fred Grayson. Could he be the murderer?”

“Sure,” Taylor said.

“Oh yeah,” Steve said. “And how is that?”

“’Cause who would know? When the third person-Rose Tindel-came up and found Jack Walsh dead, she wouldn’t know whether Fred or Jason did it. Right?”

“Wrong,” Steve said.

Mark Taylor and Tracy Garvin both looked at him.

“What?” Tracy said.

“Wrong,” Steve said. “Rose Tindel would know.”

“How the hell would she know that?” Taylor said.

“Because we have to assume that Rose Tindel is intelligent and can reason just as well as we can.”

“What’s that got to do with it?”

Steve shrugged. “Well, we just got through figuring out Jason Tindel couldn’t have done it. ’Cause if he had, Fred Grayson would know it. Well, Rose Tindel can figure that way too. She can say, ‘It can’t be Jason, or Fred would know it, and Jason wouldn’t be that stupid as to let Fred know he’d committed the crime. So it can’t be him. And if it isn’t him, it has to be Fred.’ You follow me?”

Taylor frowned. “I think so.”

“So it can’t be Fred. ’Cause he can reason that way too, and he won’t commit the crime if Rose Tindel would know it was him. You follow me?”

“Absolutely,” Tracy said. “And the same thing with Pat Grayson, right?”

“Exactly,” Steve said. “Pat Grayson knows it couldn’t be Jason or Fred would know. She knows it couldn’t be Fred, or Rose Tindel would know. So if she walks in and finds him dead, she’ll know it’s Rose Tindel. So it can’t be Rose Tindel. ’Cause she wouldn’t be that dumb.”

“You’ve absolutely lost me,” Taylor said.

“Oh, come on, Mark, it’s simple,” Tracy said. “Claire Chesterton figures the same way, right?”

“Exactly. So Pat Grayson couldn’t have done it. Likewise, Carl Jenson figures out Claire Chesterton couldn’t have done it.” Steve grinned. “Of course, there we have a problem. Frankly, I can’t see Carl Jenson figuring anything out. But grant him the hypothetical power, the answer is yes.

“And Carl Jenson couldn’t do it, because he came last. If he did it, Claire Chesterton, who knew Walsh was alive when she left, would know it was him. So he couldn’t have done it.”

Steve spread his hands. “So there we are. Here the man lies dead. And none of the six of them could have killed him, because if they had someone would know it was them. And yet the man is dead and one of them did kill him, and no one has the faintest idea who it was.”