The cover illustration shows a mummy standing next to a wooden table, with green liquid, books, and scientific equipment on it. The mummy is looking away from his diary, when he's writing in it with his left hand, and is holding a science tube, filled with the green liquid, in his right hand. The mummy is also wearing glasses and has gray hair sticking out from underneath his bandages at the top of his head.
You are on vacation in San Fransisco, California, and are extremely bored. With you on your vacation are your parents, your five-year-old sister, Susie, and your fourteen-year-old brother, Derek. One day, your family decide to visit a new skyscraper that is modeled after Ancient Egyptian pyramids. As part of the grand opening, there is a special limited edition Ancient Egyptian mummy exhibit, featuring the ancient pharaoh, King Buthramaman. You continue to look around in the exhibit and find a diary that seems to have been written by the corpse. When the security guard isn't looking, you quickly put the ancient book under your shirt so you can read it. However, the diary has some tricks up its sleeve and it illustrates the mummy's plans to come to life during the night.
List of endings
There are fifteen bad endings and eight good endings.
- The museum director keeps you as a mummy and puts you in a storage locker, wanting to make you part of the exhibition.
- As a mummy, you're captured by two museum guards who take you out in a boat, planning to sell you. But because you removed your bandages, your body is rotting fast. The guards throw you overboard into shark-infested waters, and the sharks eat you.
- As a mummy, you're examined by doctors, who find a computer chip in your brain; proving that Ancient Egyptians invented modern computer technology. You are considered a scientific wonder and you become famous. But after a while, you become tired of this and want to go back to your family. You try to write a note asking the doctors to help you - but your writing comes out as hieroglyphics, so you have no way to communicate.
- The mummy turns you and Derek into mummies too, and takes you to the top of Coit Tower, where he plans to conduct a ritual that will make him come back to life. You push him off the building, destroying him - but this makes you and Derek crumble into dust. The wind blows your dusty remains all the way to Egypt.
- You decide to let the mummy take Susie, instead of yourself. The mummy calls you a jerk, before taking Susie away with him. Then Susie helps the mummy come back to life and now she has fame and fortune. But you're left with nothing.
- The mummy pulls you into a sarcophagus. You try to yank your arm away from the mummy, but he's so strong that he pulls your arm off.
- You fall into a tar pit and are boiled alive in hot tar.
- Two criminals steal your camel and leave you stranded in the middle of the desert.
- You drink some blue lemonade, which is drugged. You fall unconscious and the diary is stolen. Because the story revolves around the diary, you can't go on any further (and the book scolds you for drinking something that obviously wasn't safe.)
- Alternatively, you don't drink the lemonade. The guy you were talking to turns out to be an FBI agent who's going to accept you onto a special training scheme. You take a celebratory sip of the lemonade - but it is drugged, and knocks you out cold. This means you failed the test to join the FBI, so you don't get to be a secret agent.
- Derek finds you in the basement and takes you back to your parents. They're furious that you left Susie alone and went off by yourself without telling anyone. They ground you for a month.
- After ending up in Egypt, you place the mummy's diary back inside his tomb, then use a magical portal to take you back to San Francisco. You take the elevator to get back to your hotel; but when the doors open, the mummy is standing in the doorway. The mummy is angry with you for stealing his diary and entering his sacred burial chamber uninvited. It's implied that he kills you.
- You ask a movie star to translate the diary for you, thinking that he'll understand it since he plays an archaeologist. He thinks you're asking for his autograph - and writes it with a marker, completely covering the hieroglyphics you wanted him to decipher.
- You're being chased by a crocodile, so you throw it some Fruity Bites candy. But the crocodile follows you around to get more, and eventually you run out. It sees you as a fruity bite and it's implied that you are eaten by the crocodile.
- You try to get past a crocodile to water, but you don't make it, and the crocodile eats you.
- You catch up to the mummy (in your body) and try to alert your family to what's happened. The mummy tells your parents to call the police. Cops arrive and think your father vandalized the mummy exhibit, so they arrest him. At this point, the mummy gives an evil laugh, making everyone suspicious of him. Your mother recognizes you as her child, even though you have been mummified she also protected you when the cop tried to shoot at you when you get up. It's implied that you switch back to your own body or still mummified ,but that the real mummy was surprise that you're mother reconized you putting a end to his trick.
- You switch bodies with the mummy again and he is sent back to his sarcophagus. But the diary contains a new entry, stating that he plans to escape again soon and get revenge.
- The mummy turns out to be an animatronic that's part of a publicity stunt. You get to join in and play with the controls.
- The mummy uses you and Derek in a ritual for him to return to life. He does, and thanks you for your help; then disappears into the city. You and Derek go back to your hotel, but the mummy display is no longer there.
- The mummy asks for your help to restore his youth, so you take him for spa treatment. It makes him look a few centuries younger (although he's still thousands of years old.) The mummy thanks you for your help and leaves. But when you get back to the hotel, there is a new diary entry. The mummy thinks you are so wise that he intends to follow you around forever.
- You know the correct words to bring the mummy back to life. He vanishes and leaves you all his treasure.
- The diary turns out to have been an elaborate prank by Derek. However, you know that the mummy really did vanish that night. You decide it was a coincidence, and enjoy your vacation in San Francisco. When you get home, you read a newspaper headline saying that the mummy was stolen on the night you visited the exhibit.
- The hieroglyphics in the diary turn out to be reviews for restaurants in Egypt.
- In one choice in the book, the phrase Klaatu Barada Nikto is used, referencing the 1951 film, The Day the Earth Stood Still.
- There are several illustrations in the book including humorous hieroglyphics and a somewhat unconventional maze.
- Contrary to the impression the book gives, the picture used on a Hieroglyphic does not have to do with a message. Each unique picture on Hieroglyphics are symbols representing letters and numbers.
- Illinois Smith is a parody of Indiana Jones.
- Some of the pages have decisions that both lead to a dead-end.
References in other Goosebumps media
- In Chillogy, Part II: "Strike Three... You're Doomed!", there is a scene in which Jessica Walters enters Matthew Erikson's room. In this scene, the contents of Matthew's bookshelf becomes visible. The shelf is filled with Goosebumps books. The only book that is clearly visible is Diary of a Mad Mummy.