Emprise by Michael P. Kube-McDowell

table.
    “We need some sort of cosmic Rosetta stone or some pure Yankee luck,” said her father. “My suggestion would be that we generate as many possible attacks on the message as we can, with each of us pursuing whatever strikes his fancy.”
    “I’ll write the list,” said the old man. “Drake picture, at the top. I don’t expect anything, though. Don’t think I’d believe the coincidence if it did prove out.”
    “It could be in the length of the tones—”
    “Or in the pattern of switching from one tone to another.”
    “I’d say look for basic physical constants—speed of light, charge of an electron. Their universe is the same as ours.”
    “Three hundred thirty-three,” pronounced the woman, looking up at last from the paper she had pored over since Agatha had settled in place.
    “Eh?”
    “That’s how many tones the message contains before it repeats. Who knows information theory?”
    “That’s base ten. Maybe there’s some clue to the pattern in another base.”
    Agatha nodded emphatically. She could hear them all perfectly, though beyond the fact that they were struggling with a mystery, she had no idea what they were talking about. But that would change. Opening her tablet, she began to take notes.
    The weeks of May slipped by, and the committee continued its meetings—nightly at first, then more fitfully. Agatha discerned their names and their problem the first night—break the code of the secret message. At least, it seemed to be secret. The night meetings behind closed doors and the occasional worried comment about others finding out sent a clear message to Agatha.
    Though they moved from room to room, she always found a place from which to listen—how the servants must have enjoyed eavesdropping in the old days!—and she recorded their growing frustration. Arguments became more frequent, more intense and less easily smoothed over, and at the end of May, the round-shouldered man—Winston—stopped coming.
    Josef Schmidt, though, took up residence with them, at her father’s insistence. He was as polite and unimposing a guest as Crown House had ever seen. Not only did he not disturb the rhythms of the household, his presence seemed to stabilize it. In him both Agatha and her father found an alternative to each other for company and conversation, and the soft-spoken German seemed equally at ease with either of them.
    School ended in mid-June. Agatha’s replanting in the Garden Room’s marble window boxes began to bear fruit—vegetables, actually—but the committee’s efforts did not. The more the solution resisted discovery, the more interested Agatha became in trying her hand at it herself. But the growing bundle of papers went into the antique but quite solid safe every night at the end of the meeting.
    That simply meant she had to find out where her father had written down the combination. Her mysteries had taught her that no one trusted memory enough not to write it down in some form, somewhere. “Somewhere” for her father turned out to be the underside of the felt lining in the knife section of the sterling drawer. She learned of it when two mid-June meetings were canceled, and memory failed him at the beginning of the third.
    That same night, Agatha crept downstairs, nearly overcome with anticipation, and spread the papers out on the library desk. She knew everything they had tried, even if she didn’t always understand why they had tried it. Now, it was hers—what should she do with it.
    Be logical , she commanded herself, echoing a favorite teacher’s dictate. If these people had really meant to send a message, how would they have started it? She began to make a list of possibilities.
    Just before dawn, she heard her father stirring, and hastily replaced the papers. She crept up a back stairway to avoid him and then ran to the safety of the Garden Room, where she burrowed under the blankets and curled up hugging a pillow.
    Thanks to the interruption, she had not