It's boiling hot up here in the Earth's northern hemisphere, so hopefully at some point you'll find yourself vacationing at a beach — or at least lounging near a large body of water. And when that happens, you'll need a really awesome scifi adventure to read while you sip a cold drink and pretend you never have to go back to your desk at the Ministry of Information. There are two rules of beach reading: One, the book must be a rollicking good adventure; and two, the tale cannot have a depressing ending. It's summer, ferchrissake! Leave the gloomy, emotionally-draining stuff for winter, OK? With those rules in mind, we've put together a list of twelve excellent books to take to the beach (or lake, or mountains) with you this season.

Oldies but goodies:

Lord Valentine's Castle, by Robert Silverberg

A terrific quest epic set on a semi-medieval planet with space travel, Lord Valentine's Castle leads you across a several continents of the planet Majipoor toward a huge mountain crowned with several massive cities. Intriguing and carnivalesque, the novel follows our amnesiac hero as searches for his true identity among artisans, spies, aliens, and magicians. Though he believes himself to be a humble circus performer, he has strange dreams of being something else — something far more powerful. Great adventure, with four-armed jugglers and beautiful maidens thrown in for good measure.

There and Back Again, by Pat Murphy

One of Pat Murphy's best novels, There and Back Again is about a regular guy named Bailey who finds a mysterious message pot in orbit around an asteroid. When he notifies its owners that he's found it, his safe little life on his asteroid gets turned upsidown. He finds himself scooped up by galactic adventurer Gitana, who has her own ideas about what to do with the message pot. That's right: She's taking Bailey and heading straight to the center of the galaxy. Get ready for spacetime distortion and a lot of serious swashbuckling.

Worlds of Exile and Illusion, by Ursula Le Guin

A collection of three of Ursula Le Guin's early space-adventure novels, this book takes you on spy missions, dangerous touchdowns on planets populated by mysteriously automaton-like people, and deep into the lives of people in two tribes that live on a planet where seasons last for years. Unlike Le Guin's later work, which grows more complex and philosophical, these novels are smart but light. And they always deliver a dose of the truly strange.

Steampunk, edited by Ann & Jeff VanderMeer

This collection of steampunk short stories just came out this month, and it's already become something of a legend. Packed with crazy, smart, diverting stories by Neal Stephenson, Ted Chiang, Mary Gentle, Michael Chabon, and Jay Lake, you won't be able to put it down. Expect zeppelins, mechanical oddities, plans to rebeautify the moon, steam-powered robot armies, and general anachronistic anarchy.

Court of the Air, by Stephen Hunt

Another steampunk winner, Stephen Hunt's Court of the Air is a tale of two adventuring orphans in a world full of pneumatic buildings, brass cyborgs, and wondrous airships. Helped along by mysterious aliens/other-dimensional beings and secret agents, fleeing the authorities and trying to figure out which side is right, our heroes Molly and Oliver go on an astounding adventure. Making this book all the more pleasing are Hunt's satirical, Dickensian moments where he makes fun of pompous politicos and greedy entrepreneurs.

Sun of Suns, by Karl Schroeder

A tale of pirates trying to steal an artificial sun to light a rebel colony that lives on a bunch of rocks and giant spinning cylinders inside a planet-sized bag of gas floating in the middle of space? The answer to that strange question is, of course, yes. This is the first of a trilogy, so if you can't get enough of the crazy world-building and rebellious pirates and airships with canons, you can always get more.

Kushiel's Dart, by Jacqueline Carey

We've recently told you how great the sixth book is in the Kushiel series, but this is the brilliant and bizarre adventure that started it all. It's the tale of a prostitute-spy whose superpower is that pain gives her intense sexual pleasure. Sent on a mission to save her country from imminent invasion, she's accompanied only by a mysterious, celibate monk who is as good with his knives as she is with her mind (and her, um, other parts). Can you have an alternate history, naughty sex romance that's also an awesome spy thriller? Yes you can!

Komarr, by Lois McMaster Bujold

Lois McMaster Bujold's most beloved character, the disabled but badass Miles Vorkosigan, returns in the first novel of a new trilogy about his entanglement in the politics of the planet Komarr. Dispatched there to investigate an accident, Miles is sucked into a plot involving terraforming, weapons of mass destruction, and even the liberation of an abused wife. There's a lot of amazing world-building and detective work, plus a little romance too. The sequel to Komarr, A Civil Campaign, is also great, though a bit more romancey.

Coming out in July and August:

The Alchemy of Stone, by Ekaterina Sedia

The tale of a clockwork woman named Mattie whose heart is literally kept locked up by her maker, The Alchemy of Stone is set in a spy-ridden world of intrigue and class warfare. As a scientific revolution sweeps through the city of Ayona, Mattie discovers a secret that could help her lead a coup. If only she could figure out who to trust, and regain the key to her own heart. Written by the author of The Secret History of Moscow, this novel is beautifully strange.

Incandescence, by Greg Egan

You want to take a ride to the freaky heart of the galaxy, to the mysterious "bulge" where a strange species of creatures lurk, refusing all contact and yet harboring amazing secret knowledge? Hell yes you do. And that's what you'll get in Egan's latest novel, about a man who gets the chance to visit that bulge and meet the creatures within it. What he discovers are members of a lost race, searching for scientific enlightenment that might save their world. Expect galaxy-spanning coolness.

Saturn's Children, by Charles Stross

A sexbot on a spy mission? Sounds like Kushiel's Dart, except it's by Charles "Halting State" Stross and it's set in a post-human solar system where homo sapiens has gone extinct and bots rule the day. Femmebot Freya's clientele have all gone the way of the Dodo, so she takes a dangerous courier job — she's got to get a small package from Mercury to Mars, and she can't let those dangerous humanoids who are tracking her get to it first.

Sly Mongoose, by Tobias Buckell

Nothing like floating cities, gas giant storms, and vast alien intelligences to make a damn fine adventure. Set on a planet packed with all three, Sly Mongoose is the tale of Timas, an unlikely hero whose life goes sproing when a man crash-lands in his airborne city. Timas must help avert an interstellar war by plunging deep into the high-pressure mega-storms of his planet in search of alien secrets. Great world-building and fast action make this an excellent book to keep you diverted — but also to make you think too.