A ham radio is a real machine. It is not a prop invented for the plot. People still build them, still get licensed to run them, and still use them to talk to strangers hundreds of miles away with nothing in between but air.
Book three hands one to a third grader who cannot get it working. Then, during a sleepover in the middle of the night, Nina hears a voice come out of it saying "Release the swarm," and decides that an invasion is on the way.
The science it actually teaches
The object is the lesson here, which is different from the other books in this series.
Start with what a radio does, because most children have genuinely never thought about it. A voice leaves a machine somewhere far away and arrives in your bedroom with no wire attached. That is not a small idea and it is not obvious. Waves carry it, air does not stop it, and distance is a thing you work against rather than a wall. A child who has watched a person talk into a box and heard a stranger answer has met the electromagnetic spectrum in the only way that ever means anything at seven, which is by using it.
Then the part I would buy this book for. The radio does not work, and Ada has to fix it. She has to fix it, not replace it, and you cannot fix a thing you do not understand. Repair is the rarest skill in children's science fiction and close to the rarest in children's lives now, because almost nothing in the house opens. A book where the machine is broken for most of the story, and the heroine's job is to work out why, is teaching a habit that no worksheet reaches.
The third thing is the one that makes this the more interesting half of a pair with the first book. In on the Case, Nina's alien theory is a joke and Ada can wave it away, because there is no evidence for it at all. Here there is evidence. A voice really did come out of that radio, in the dark, and it really did say something strange, and both girls heard it. Ada cannot dismiss it and stay honest. She has to do the harder thing, which is to take a strange observation seriously and still not leap to the biggest possible explanation for it. That is precisely how the people who actually listen for signals from space are obliged to work: every ordinary explanation gets ruled out first, and it usually turns out to be one of them.
Two people heard exactly the same sound and came away with two different worlds. The sound was the data. The invasion was not.
The child it lands with
The one who takes the back off things. The one with a screwdriver and a shoebox of parts that used to be something else.
It also lands with a child who wants a hobby with a machine in it and has not found one. Amateur radio is a live thing, there are people doing it in most towns, and it is one of very few technical hobbies a nine year old can genuinely be part of rather than watch. If your child comes off this book asking about it, that is not a phase to wait out. That is the book working.
And it lands, differently, with the alien child. The one who wants it to be aliens. This book takes that wish seriously for a long time, which is more respect than most science books show it.
One place to stop and talk
Stop the moment the voice comes out of the radio, before anybody in the book reacts, and get your child to list every explanation they can think of. All of them, including the silly ones. Write them down where you can both see them.
Then ask one question: which of these could we check tonight?
That is the whole of science compressed into six words, and it is also the reason a strange noise stops being frightening. A child with a list and a way to test the top item on it is not lying awake. A child holding one enormous explanation and no way to check it is, and the difference between the two is something you can hand over in ten minutes.
What to know going in
The nighttime is the caution on this one.
A disembodied voice in the dark saying "Release the swarm," heard during a sleepover, with a friend who is immediately certain the invasion has started, is genuinely creepy for a child who already lies awake. It is not gory and nothing violent happens. It is atmospheric, and atmosphere is exactly what gets into a seven year old at eleven at night. Read the first couple of chapters in daylight, or read them together, and you will most likely never think about it again.
The other thing is expectation. If your child wants a book where the aliens turn out to be real, I am not going to tell you whether this is that book. What I will tell you is that the pleasure here is the machine, not the invasion, and a child who only came for the invasion may feel short-changed by the last chapter.
The store band of grades 2 to 5 runs generous at the top, the same as the rest of the series. Treat it as a grade 2 to 4 independent read. And this is book three, so it is better with the first one behind it, though it stands on its own well enough.
Where to get it
Ada Lace, Take Me to Your Leader costs $6.99, which is a cheap way to find out whether there is a radio child in your house. If yours closes it and starts asking about getting licensed, that seven dollars has bought you a hobby with real equipment and real people in it, and I would let it run. This is book three, better with book one behind it, fine enough on its own. The other three are under Stealth Science too.
If your child liked this one
Books we have written about that sit close to this one, by reading level and by subject.
Ada Lace and the Impossible Mission: Scale and Sensors
Ada Lace and the Impossible Mission by Emily Calandrelli
Grade 2 to 5
Amazing Magnetism: Science You Can Check With a Magnet
Amazing Magnetism (the Magic School Bus Chapter Book #12) by Rebecca Carmi
Grade 2 to 4
The Giant Germ: How an Infection Actually Works
The Giant Germ (the Magic School Bus Chapter Book #6) by Joanna Cole
Grade 2 to 4
Browse every book we have written about by age, by kind of book and by subject: Find the right book for your child. Or see the whole Stealth Science shelf.
