The Case of the Muttering Mummy by E.W. Hildick, 1986.

Joey Rockaway needs to buy a special present for his mother’s birthday. Having broken his mother’s china cat ornament recently, he has decided that he will buy one of the replicas of a golden cat statue from Egypt at the Egyptian exhibit at the local museum. The other members of the McGurk Organization come to the museum with him, and McGurk uses this as an opportunity to give them a kind of memory test about objects in the exhibit.

Actually, everything in the exhibit is a replica, not just the items sold in the museum gift shop. Justin Matravers, a wealthy man who has recently died, collected Egyptian artifacts, but part of his will specified that the collection should never be put on public display. However, his widow, who wanted to show off the collection, had replicas made of everything in the collection so that she could have those put on display.

McGurk sneers about how everything in the exhibit is fake, although he is actually surprisingly superstitious. The museum always did have a real mummy case on display. They always said that the mummy case was empty, but some of the more superstitious kids, like McGurk, believe that there is a mummy inside the case and that there is a curse on it. McGurk has nicknamed the mummy Melvin. The other kids aren’t afraid of Melvin or Egyptian curses, and while they are looking around the Egyptian exhibit, Mari plays a joke by using her ventriloquist skills to make the mummy case “talk.” This trick sets off a bizarre mystery for the McGurk Organization.

A scholar and author, Harrison Keech, is sketching the replicas at the exhibit and witnesses Mari’s trick and Joey picking out the replica cat for his mother. After he asks Joey if he can take a look at the cat, Keech suddenly becomes very upset, saying that the cat statue is cursed! He says that Mari’s joke has angered the spirit of the mummy and awakened the spirit of Bastet. The mummy was a follower of Bastet, the Egyptian cat goddess, and it will now be drawn to the statue if they remove it from the museum. Mari tells Joey that she can tell from Keech’s voice that he’s making up the whole story and that he shouldn’t let that stop him from buying the cat.

However, strange things start happening after Joey buys the cat. It seems like someone is following him home, a dark, shadowy figure. Joey thinks it might even be the mummy, come back to life! The others are skeptical, and McGurk arranges a kind of test where Joey brings the statue with him to a meeting of the organization. Sure enough, a strange figure lurks outside their meeting, and they hear strange whispers in a foreign language!

The spookiness doesn’t last for long. It turns out that Mari, as well as being a ventriloquist, has some skill with different languages and recognizes what the “mummy” says as being Greek, not Egyptian, and the phrases as being typical things that someone might say in a restaurant. When the kids find a scrap of bandage outside, they are quick to notice that it’s a modern, elasticized bandage, like the kind you can get at any pharmacy.

So, the question becomes who is playing at being a mummy and why? Is it Keech, wanting to make the kids think that the mummy story he told them is real, and if so, what would he have to gain from it? The only other two people who know about the story are Joanne, who works at the museum, and Donny, her fiancé, who is jealous of the attention she’s been paying to Keech when he comes to the exhibit.

I have some complaints about this book that hadn’t occurred to me when I read it as a kid. At one point, Donny, who is described as being a social worker, comes to visit the kids because he wants to hire the organization to check up on Keech and his relationship with Joanne. Donny is very jealous, and when he explains how Joanne seems to be falling for all of Keech’s crazy mummy stories, he suddenly turns to Wanda and Mari and says, “You women, you’ll believe anything when a smarmy two-bit jackass like that starts shooting his mouth off!” That’s just really inappropriate for an adult to say to kids, and the whole situation is weird on several levels. First of all, Donny is an adult, and if he’s having issues with his love life, especially with the woman he thinks he wants to spend the rest of his life with, the last thing he should do is hire kids (even really smart ones) to handle the issues for him. Second, Wanda and Mari are young girls, not “women,” and what little girls believe is no business of Donny’s. Trying to imply that Wanda and Mari might someday fall for a “jackass” is not only insulting but implies that Donny is thinking about Wanda and Mari in terms that no grown man should be thinking about girls their ages. I find it disturbing that Donny is apparently a social worker, a person in a position of trust who is supposed to help people in difficult situations to manage their lives, and he’s acting like this. Also, toward the end of the book when the bad guy (I won’t say who it is here, although I thought that the answer was pretty obvious even early in the story) is making his escape, he shoves Joanne aside and calls her a “slut.” That’s pretty strong language for a kid’s book of this level. None of this occurred to me when I was a kid, so maybe other kids reading this wouldn’t notice, but I thought that I’d mention it because these things bother me now.

At one point, Brains gives a demonstration of using water displacement to determine the volume of irregularly-shaped objects, explaining how Archimedes discovered the principal (although I’m not sure that Archimedes’ Principal was quite as he explains it), as the kids investigate what makes Joey’s cat statue so special. You might be able to guess what it is. It seemed pretty obvious to me. The one thing that seemed the most puzzling was how it was done. Mari also offers an interesting explanation of the different kinds of lies that people tell and their motives for doing so.

The book is currently available online through Internet Archive.