Principal Hart needs a detective. Turn your sound on.

Lessons you need for this case

The five notes in this case are written in five secret codes. You must have finished all five code lessons to solve the whole mystery. If you skipped one, go back and learn it now.

Check the box next to each lesson you have finished.

    Check all five lessons to open the case.

    How this case works

    1. Read about the case and meet the eight suspects.
    2. Crack the five notes. Each one is written in a different code, and nobody will tell you which code is which.
    3. Answer three questions. Who took the air pump? Where did they hide it? Why did they do it?

    Be careful with step 3. A wrong answer locks the answer box for 3 minutes. Guessing will not work. Cracking the notes will.

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    Teacher note

    Answers are inside. Enter the teacher password.

    What happened

    On Thursday morning, Coach Ramos opened the PE shed at Juniper Elementary and could not believe his eyes. Every football was flat. Every kickball was flat. Every soccer ball was flat. All 31 balls.

    He reached for the air pump to fill them back up. The hook was empty. Somebody had taken the pump and hidden it.

    Now recess is boring. There is nothing to kick, nothing to throw, and nothing to catch. Then Coach started finding pieces of paper around the school, covered in strange writing.

    What we know

    The ballsAll 31 are flat. None are cut or popped. Somebody let the air out with a pump needle, one ball at a time.
    The PE shedIt is left open before school so student helpers can set out the cones. Anyone could have walked in.
    The air pumpGone from its hook. It is as long as your arm, so it did not leave in anybody's pocket. It is hidden somewhere at school.
    The notesFive pieces of paper, found in five places. All five were written with the same purple pen.
    A pump needleFound in Dash Torres's backpack. It is the kind of needle you use to let air out of a ball.

    Principal Hart says: "Dash was benched from kickball this week, and he had a pump needle in his backpack. I think we all know who did this."

    The timeline

    • Wednesday, 3:30 PM. Coach Ramos puts away 31 bouncy balls and goes home.
    • Thursday, 7:15 AM. The shed is opened for the student helpers.
    • Thursday, 7:20 to 7:50 AM. Kids and teachers are all over the school. Nobody is watching the shed.
    • Thursday, 7:55 AM. Coach Ramos finds 31 flat balls and an empty hook.
    • Thursday, 8:00 AM. Nora Flint brings the first note to the office. She says she found it taped to the shed door.
    • Thursday, 10:15 AM. Recess. It is the most boring recess anyone can remember.
    • Thursday, after lunch. Coach has found four more notes.

    Eight people are on the list

    Each of them had a reason, or was near the shed on Thursday morning. An alibi is proof that you were somewhere else when it happened. Look at who has one.

    Principal Hart says: "Read them all if you like. But I keep coming back to Dash. He said it himself. If he cannot play, nobody plays."

    The five notes

    Every note has a secret message. First work out which code it is. Then crack it. The keys are in the Code toolkit tab. You need all five notes to answer who, where, and why.

    Notes cracked: 0 of 5

    Caesar Wheel Review the lesson

    Every letter slides the same number of steps down the alphabet. Find the secret number, then slide the strip. Look up each code letter on the top row. The real letter is right under it.


    Pigpen Cipher Review the lesson

    Each letter is drawn as the shape of the pen around it. Shapes from the second grid and the second X have a dot. Use this key for this case.

    Polybius Square Review the lesson

    Every letter is two numbers. The first number is the row. The second number is the column. I and J share a box.

    Spartan Scytale Review the lesson

    The letters are not changed. They are only mixed up. The message was written on a strip of paper wrapped around a rod. Wrap the strip around a rod of the same size and the words line up again.


    Read across each row, starting at the top. If the rod is the wrong size, you get nonsense.

    Rail Fence Cipher Review the lesson

    The letters are not changed. They are written in a zigzag on the rails of a fence, then read one rail at a time. Here is HELLO WORLD on two rails.

    H . L . O . O . L . . E . L . W . R . D

    Read the top rail, then the bottom rail, and you get the code: HLOOL ELWRD. To crack one, count the letters and split them into a top rail and a bottom rail. If the count is odd, the top rail gets the extra letter. Then zigzag: top, bottom, top, bottom.