Dead Past

across the top represent the plain text. The uppercase letters in the columns represent the cipher text.”
    Neva made a gesture with her hand going over her head. “This looks too much like math with letters,” said Neva.
    “Not far from wrong,” said Frank.
    “This is great,” said Jin. “Where have I been that I didn’t know this?”
    “I don’t know,” said Frank grinning. “This is Secret Code 101.”
    “How does it work?” said Diane.
    “Let’s say the keyword is DIANE. In the left column I will use only those letters.” He used the word processing program to highlight the letters of DIANE and continued the shading all across the row in the table for each letter.
    “Now, suppose we have the message, ‘The house that Jack built.’ So, we have to make another table . . . ,” began Frank.
    “OK,” said Neva. “You mentioned something about a computer program that would do this?”
    “Yes, but I don’t have it,” said Frank. “Let’s have a little patience. Think of this as fun. Jin does.”
    “You betcha,” said Jin. He pulled up a chair and leaned forward, staring at the screen. “You said you use a second table?”
    “Yes,” said Frank. “If the keyword is DIANE, on the header row of this table I write the word DIANE over and over again until I have used up all the letters in the message to be encoded.
    “Oh, I get it.” Jin jumped up and sat down again. “That’s brilliant. No wonder I couldn’t make heads or tails of it.”
    “Explain it to those of us who don’t get it,” said Neva.
    “To encrypt ‘The house that Jack built,’ ” said Frank, “I go to the new table and see that the first letter in the message is t and it is under the letter D in the keyword DIANE. I go to the Vigenere square and use it like the coordinates of a map to find the encryption letter I need. Go to D on the left most column and find where it intersects with t in the top row. The letter where the column and row intersect is W . Do the same thing for the second letter. The h is under I in the keyword Diane. Go to the square and we find that I and h intersect at P . Keep going and you can encrypt the whole sentence. You do the reverse process to decode the message.”
    “That is so cool,” said Jin. “You’ll have to show me how to decode it the other ways you were talking about.”
    “Sure. It’s more time-consuming. As you see, if you have the keyword, it’s a piece of cake.”
    “Yeah,” said David, “I’d like to see the computer program. That would be an interesting algorithm.”
    “How about our message?” said Diane.
    “OK, we’re hoping the keyword is palimpsest .” Frank took the first word in the doll code and tried it out with his square. KVQ = vvf. “ Palimpsest isn’t the keyword,” he said.
    “Try papyri, ” said Diane.
    “Won’t work,” said Frank. “ Papyri and palimpsest start out with the same two letters. We’ll end up with vv again.”
    “So we’re nowhere,” said Neva.
    “Or an alternative method for decoding it,” said Jin.
    “Maybe the keyword is his name,” said Neva.
    “That would be too easy to decode,” said Jin. “If you are going to the trouble to have an elaborate code, you won’t have such an easy keyword.”
    The phone rang and Diane answered. She was expecting Garnett, but it was Beth, the museum’s librarian.
    “Beth,” said Diane. “You have something for me?”
    “Yes, I do. I can bring it to you. I thought you’d like to know that I did find some descendants of Leo Parrish that you might be able to contact. I don’t know where they are now, but I have info on the last-known locations of some of them.”
    “Great. Can you come to the crime lab?” Diane asked.
    “Yes. I’ll walk right over,” said Beth.
    Diane explained to the others that she’d enlisted the help of a genealogist to discover any relatives of Leo Parrish.
    “That was clever,” said Frank.
    “And fast,” said Diane. “Librarians are much speedier than private detectives.”
    It took only a couple of minutes for Beth to cross from the third-floor east wing to the west wing where the crime lab was. David was at the door to let her in. She entered, looking around at all the glass walls and high-tech equipment as though she’d just stepped onto another planet.
    “Well,” she said, “this is certainly different from the rest of the museum.” She was carrying a folder, which she held close to her. They all moved to the round table to