Whilst visiting your cousins in Arizona you go exploring in a cave, find an animal skull, and drop it. Suddenly, a Shaman appears and says that you have displeased the Cave Spirit; for which you are to be turned into a petroglyph on the cavern wall. Your only hope of avoiding this fate is to become a "worthy opponent" to the Cave Spirit and defeat him in a fair fight. From here, you have a choice of turning into either a hunter or spell caster, and have to pick from a list of items to use. Like the books in the main series, this one has two storylines.
You choose to become a hunter, and pick three out of four magical weapons to use in addition to a sword that the Shaman gives you. The Cave Spirit will appear to you as an animal, meaning that all animals (including pictures and anything at all that could have an animal on it) are dangerous to you. You then try to survive as the Cave Spirit takes the form of different animals to attack you.
You choose to become a spellcaster and are given a wand, then have to choose from three of four talismans which can cast spells for you. However, these spells may backfire, and when using the wand you have to be very careful how you phrase your words.
- As a hunter, you use the wrong weapon in your battle against the Cave Spirit, and end up as a petroglyph on the cavern wall.
- You're attacked by a giant bird which drags you off the edge of the mountain to your death. It dawns on you too late that birds are animals, and this one was the Cave Spirit.
- You're caught in the Sticky Net and swallowed by the Cave Spirit, who has transformed into a snake.
- The Cave Spirit has taken the form of a lion, and you try to use the Ice Rifle against him. The lion causes you to drop the rifle, which fires and freezes the whole room around you. You are so stiff with cold that you can't hold the rifle, so instead you pick up your last bullet, expecting to throw it at the Cave Spirit and freeze him. Instead, you are frozen solid and the lion eats you.
- You save a mountain lion from being swept over a waterfall, hoping that the Cave Spirit will have mercy on you for your kindness to an animal. The lion is so grateful that it carries you off to its den to raise you as one of its cubs.
- You're crushed to death when an ancient mastodon falls on top of you.
- You chase away the mastodon, but it crashes through the cliff and causes a massive rockslide which buries the only exit from the Lost Land. You are now trapped there forever with Professor Greenwell and the others, because you'll never be able to dig through the rubble.
- You aim the Flaming Arrow at the Cave Spirit (who is possessing the body of a Doberman), but miss and set fire to a tree. A forest fire rapidly breaks out. The dog leaps at you and pushes you into the fire; you burn to death before anyone can help you.
- You run smack into a Triceratops and are speared on its horn (the book goes into gory detail about what a horrible death this would be.)
- You use the wrong weapon against a pterosaur; its skin is too thick for this weapon to be effective. You don't get another chance before the pterosaur eats you.
- A pterosaur scoops you up in its beak, but then drops you accidentally. You use the Sticky Net to break your fall. A crowd of people that had gathered around the pterosaur all start to laugh and applaud. The pterosaur sucks you back up into its mouth and spits you out again, forcing you to repeat the process over and over because it likes the attention so much.
- You fail to work out a puzzle telling you which animal the Cave Spirit would have turned into next, so the pterosaur eats you.
- You use the watch talisman to stop time, but accidentally break the watch and time is stopped forever. This leaves you trapped in your own body for the rest of eternity, unable to move or blink.
- You try to use your wand to make the skeleton stop in its tracks, but hit yourself with the spell because you were holding the wand the wrong way around. This immobilises you and the skeleton turns you into another skeleton.
- You're stuck in a ghost prison for ninety years until the Cave Spirit returns and will be able to free you.
- Stuck in a pit full of poisonous scorpions and tarantulas, you use the watch spell to freeze time. You kill the creatures, but then can't get out of the pit, and are burned to death by the scorching sun.
- Alternatively, you use the shrinking spell, but this shrinks you instead of the creatures. You are killed by a scorpion, which is now many times your size.
- Alternatively, you use the wand, but its magic will not work unless you can correctly answer a question from Dr. Comstock. You give the wrong answer, so you're powerless and all the creatures sting you to death.
- Magical caterpillars form a cocoon around you and you will be turned into a butterfly.
- The sorceress casts a spell to turn you into a frog. You try to use the wand against her but it is not working. In desperation you throw the wand at her, but this enables her to finish the spell, and you become a frog.
- You save the sorceress from the fire with the promise that she won't turn you into a frog. But she points out that she didn't promise not to turn you into anything else — so she changes you into a snake instead.
- You jump into a pond to escape from the Fire Spirit, but because you can't swim, you sink to the bottom and drown.
- Rather than accept the Cave Spirit's challenge, you try to take him by surprise and push him down the mountain. But you trip over and your talismans fall out of your pocket so that you can't perform any spells. The Cave Spirit is so enraged by your attempt to cheat him that he turns you into a petroglyph.
- A Jeep heads magically towards you, and you jump on board out of its path. It drives you through the desert and into a sandstorm. You cannot steer the Jeep (as the wheel is clogged with sand) nor hit the brakes (you're not tall enough to reach them) so you crash into a solid wall of rock and die.
- You end up changing places with the Cave Spirit, leaving him in your human body and you as an all-powerful evil spirit. You start plotting all the evil things you'll do if you can catch him.
- Facing off against the Cave Spirit as a spellcaster, you don't know which words to use with the wand. You repeat the only magic words you know, but the Cave Spirit tells you that they will work only with the talismans — not the wand. He decides that you've failed his challenge, so he turns you into a petroglyph.
- You successfully defeat the Cave Spirit as a hunter. The shaman tells you that you're free and can now continue the hunt in peace; but first, you want to find yourself a snack.
- You successfully defeat the Cave Spirit as a spellcaster. You go home to find that you missed a visit from your grandmother, who left presents for you and your cousins. Her present for you is a magic kit, and you don't know whether to be scared or amused.
- There are 26 bad endings and 2 good endings.
- An instruction on Page 36 for you to go to Page 104 (which has nothing to do with the story you're in) is wrong, and should instead tell you to go to Page 108 (the logical continuation of the story you're involved with.)
- In turn, Page 97 directs you to Page 37; but should correctly direct you to Page 104.
- The Spellcaster path allows you to avoid most of the obstacles, whereas the hunter path can be considered the harder of the two due to more items being situational or limited use.