The new Captain Underpants book proves that time travel can still be a blast

Time travel is one of the funnest concepts in science fiction — you can meet yourself, you can have Joan of Arc wreak havoc in a shopping mall, you can shred on the guitar in the 1950s. But all too often, people get hung up on trying to be clever, or fancy, or deep.

Leave it to Captain Underpants to show us the way. Minor spoilers ahead...

The latest Captain Underpants book, Captain Underpants & The Revolting Revenge of the Radioactive Robo-Boxers by Dav Pilkey, is a pretty hilarious read. I hadn't been keeping up with the Captain in years, but I was able to jump right in and get up to speed pretty fast — the first few pages give you pretty much everything you need to know about the Captain and his adventures.

I already knew, from my forays into the Underpantverse, that these books were hilarious and silly and totally irreverent and kind of obsessed with toilets and underwear. But I hadn't fully taken on board quite how ridiculous and insane and science fictional these books get. And how much fun they are for adults, as well as kids. With a nice amount of subversiveness thrown in.

So for the childless readers out there, or anybody who's been living under a rock, the heroes of these books are actually two nerdy kids named George and Harold. The origin of Captain Underpants is as followed: George and Harold get tired of being yelled at by their mean elementary school principal, Mr. Krupp. So they hypnotize him so that whenever they snap their fingers, he thinks he's a goofy superhero named Captain Underpants, clad only in red curtains and the eponymous undergarment. Later, Captain Underpants gets fed some weird chemicals from a UFO, so he actually does have superpowers, like flying and superstrength.

The latest Captain Underpants book, out next week, picks up where the last one went off — Professor Poopypants, who has changed his name to the far-more-dignified Tippy Tinkletrousers, went back in time wearing just the robotic pants of his former robot battlesuit. And because Tippy Tinkletrousers changes history, Captain Underpants never exists, and the world gets taken over by zombies. It's your typical horrible alternate reality caused by time travel. So in this book, it's up to Tippy Tinkletrousers to fix his mistake and correct the timeline. And that's where the insanity really begins.

The new Captain Underpants book proves that time travel can still be a blastS

I won't give any major plot spoilers, but suffice to say this particular book is all about time travel. Time travel via robot trousers, via purple porta-potty, and via giant squid. And the result is like a more underpants-oriented version of Bill and Ted, with our heroes cris-crossing time and causing history to become sillier and sillier. People meet themselves, and even team up with themselves. There are dinosaurs and cave people, and the world of the future, where fast food is even more nasty than it is now. There are giant mad scientists in robotic pants riding on dinosaurs.

Let me just repeat that: There are giant mad scientists in robotic pants riding on dinosaurs.

What are the rules of time travel in the Captain Underpants universe? I couldn't tell you. I think the main rule is: if it's ridiculous or sets up a good joke, then do it. I haven't seen anyone play this fast and loose with time travel in ages. And there are some really good gags in here. Dav Pilkey takes full advantage of some of the most ludicrous implications of being able to cross your own timeline. He also plays around with history, without involving any famous historical figures. There are no time paradoxes in this book, which makes me very happy. There are no grandfather paradoxes, or things that only happen because of things that they caused. It's all very linear, and yet extremely loopy.

The cover of the book promises "Laffs," which are certainly present. And "Action," which is represented by some very comic-booky violence, some of it in flip-book form. It also promises "Mysteries of the Universe Solved" — and those are very much in evidence, too. As the start of the book says, by the time you finish this book you will be smarter than every scientist in the world, because you'll understand the origins of the universe and what happened to the dinosaurs and stuff.

But the book also contains various and sundry mysteries of the universe — chief among them, the answer to "Why are grown-ups such poopy-pants"? Why do grownups always tell kids to be quiet just when they start having fun, and why are grownups so mean all the time? Don't they remember what it's like to be kids? And because this is a time travel book, and Pilkey is pretty deft with this stuff, you actually get a bit of an answer to some of those questions.

In other words — childless readers, time to rent one of your friend's kids so you have someone to read this book to. It has dinosaurs and growth rays and shrink rays and the most ludicrous superhero ever. And it's the most fun time travel story I've read in quite a while.