Excerpt from The Bone Clocks by David Mitchell, plus links to reviews, author biography & more

By three o'clock, my whole head's parched, not just my mouth. I've never walked so far in my life, I reckon. There's no sign of a shop or even a house where I can ask for a glass of water. Then I notice a small woman fishing off the end of a jetty thing, like she's sort of sketched into the corner where nobody'll spot her. She's a long stone-throw away, but I see her fill a cup from a flask. I'd never normally do this but I'm so thirsty that I walk down the embankment and along the jetty up to her, clomping my feet on the old wooden planks so as not to scare her. " 'Scuse me, but could you spare a drop of water? Please?"

She doesn't even look round. "Cold tea do you?" Her croaky voice sounds from somewhere hot.

"That'd be great, thanks. I'm not fussy."

"Help yourself, then, if you're not fussy."

So I fill the cup, not thinking about germs or anything. It's not normal tea but it's the most refreshing thing I've ever drunk, and I let the liquid swoosh all round my mouth. Now I look at her properly for the first time. Sort of elephanty eyes in a wrinkled old face, with short gray hair, a grubby safari shirt, and a leathery wide-brimmed hat that looks a hundred years old. "Good?" she asks.

"Yeah," I say. "It was. Tastes like grass."

"Green tea. Lucky you're not fussy."

I ask, "Since when's tea been green?"

"Since bushes made their leaves that color."

There's a splish of a fish. I see where it was, but not where it is. "Caught much today?"

A pause. "Five perch. One trout. A slow afternoon."

I don't see a bucket or anything. "Where are they?"

A bee lands on the brim of her hat. "I let them go."

"If you don't want the fish, why do you catch them?"

A few seconds pass. "For the quality of the conversation."

I look around: the footpath, a brambly field, a scrubby wood, and a choked-up track. She must be taking the piss. "There's nobody here."

The bee's happy where it is, even when the woman stirs herself to reel in the line. I stand off to one side as she checks the bait's still secure on the hook. Drips of water splash the thirsty planks of the jetty. The river slurps at the shore and sloshes round the wooden pillar things. Still seated, and with an expert flick of the wrist, the old woman sends the lead weight loopy-looping away, the reel makes its zithery noise, and the weight lands in the water where it was before. Circles float outwards. Dead calm ...

Then she does something really weird. She takes out a stick of chalk from her pocket and writes on a plank by her foot, my. On the next plank along she writes, long. Then on the next plank, it's the word name. Then the old woman puts the chalk away and goes back to her fishing.

I wait for her to explain, but she doesn't. "What's all that about?"

"What's what about?"

"What you just wrote."

"They're instructions."

"Instructions for who?"

"For someone many years from now."

"But it's chalk. It'll wash off."

"From the jetty, yes. Not from your memory."

Okay, so she's mad as a sack of ferrets. Only I don't tell her so 'cause I'd like more of that green tea.

"Finish the tea, if you want," she says. "You won't find a shop until you and the boy arrive at Allhallows-on-Sea ..."

"Thanks a lot." I fill the cup. "Are you sure? This is the last of it."

"One good turn deserves another." She turns a crafty sniper's eye on me. "I may need asylum."

Asylum? She needs a mental asylum? "How d'you mean?"

"Refuge. A bolt-hole. If the First Mission fails, as I fear it must."

Crazy people are hard work. "I'm fifteen. I don't have an asylum, or a, uh, bolt-hole. Sorry."

"You're ideal. You're unexpected. My tea for your asylum. Do we have a deal?"

Excerpted from The Bone Clocks by David Mitchell. Copyright © 2014 by David Mitchell. Excerpted by permission of Random House. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.