Except today.

“Somerset has amazing birds,” I say, leading her toward the ponds. “There are loads of rare species around here, so as we walk, you should look up, all the time. Look up.”

Not down at your feet. Not down at the mud and slippery oil that I may possibly have planted earlier.

As we round a clump of bushes, the ponds come into sight ahead of us. The swamp is a patch of lime-green weed. It couldn’t look more glistening and noxious. No one’s about. All the other glampers are miles away, doing their foraging in Warreton Forest, and no one else has access to these woods. The silence around us is eerie and expectant. All I can hear is my own breath and our footsteps on the increasingly muddy ground, sloping downward toward the swamp.

“Look up,” I keep exhorting her. “Look up.”

Everything becomes boggy around here. And very slippery, even before it’s been laced with hemp oil. It’s OK, as long as you’re careful, don’t walk too fast, and don’t even think about running.

Which is why I’m about to make Demeter run.

“Oh wow!” I whisper as though in sudden excitement. “Can you see the kingfishers? Millions of them! Hurry!” I up my pace to what looks like a run, although I’m careful to plant my feet carefully and stay balanced. “You go first.” I turn and make a generous gesture to Demeter. “Go ahead of me. But hurry! Hurry!”

Like a shopper at the Harrods sale, Demeter starts pegging it in a tiptoe run, her eyes fixed upward, gathering momentum. She doesn’t see the point at which soggy mud turns to oil slick. She doesn’t even notice when she starts to skid—until her feet finally hit the slipperiest bit of the oil slick, and she hasn’t got a chance. She slides down toward the swamp, flailing her arms, looking like a really terrible snowboarder.

“Oh my God!” she gasps. “Oh my—oh God!”

“Careful!” I call out cheerfully. “It gets slippery….Oh no!”

I’m watching with all my attention, not even letting myself blink. I want to enjoy this fully. I want to see every single moment: Demeter thrashing her arms in panic…Demeter sliding off the bank…Demeter poised in midair…Demeter’s horror as she realizes what’s about to happen…

And Demeter landing in the swamp. With not so much of a splash as a thwump. It’s three solid feet of mud, and as she crashes into it, the mud sprays up in great gloopy splatters, landing on her face and hair. There’s green weed on her head and down her cheeks, and I can see some sort of bug crawling along her shoulder.

Yes! This could not have gone better. Look at her!

She immediately tries to scramble to her feet, but it’s not so easy—and she falls several times before she manages to stand up. By this time she’s in the middle of the swamp, and if I’d planned the perfect photo op, then this would have been it. Demeter looking drenched, muddy, undignified, and furious.

“Help me out!” She waves an indignant hand at me. “I’m stuck!”

“Oh dear!” I call back, getting my phone out. Trying to hide my euphoria, I take a few photos, then carefully stash my phone back in its bag.

“What are you doing?” shouts Demeter.

“Just coming to help you,” I say soothingly. “You know, you should be careful around swamps. You should never hurry.”

“But you told me to hurry!” Demeter explodes. “You said, ‘Hurry!’ ”

“Never mind. We’ll soon get you back to your yurt. Come on,” I beckon.

“I’m stuck,” Demeter repeats, giving me an accusing look. “My feet have sunk into the mud.”

“Just lift up your leg.” I mime pulling a leg out of a swamp, and Demeter copies—but as she wrenches her leg out, her wellie is missing.

“Shit!” she says, flailing her arms again. “My boot! Where’s my boot?”

Oh for God’s sake.

“I’ll get it,” I say, feeling like a mother with a three-year-old. I wade into the swamp, reach Demeter, and feel around in the mud for the boot. Demeter is meanwhile standing on one leg, clinging to my arm. “Here.” I fish out the missing wellie. “Shall we go?”

I turn toward the bank, but Demeter doesn’t turn with me.

“Why did you tell me to hurry?” she asks in even, ominous tones. “Did you want me to fall in?”

I feel a tiny spasm of alarm, which I quell. She can’t prove anything.

“Of course not! Why would I want that?”

“I don’t know,” says Demeter in the same ominous way. “But it’s weird, isn’t it? And you know what else? I feel like I know you from somewhere.”

She scrutinizes my face and I bow my head hastily under my baseball cap.

“Well, that’s ridiculous.” I give a hasty laugh. “I’m a Zummerzet girl. Never been to Lunnon town in my life. I don’t even know where Chiswick is.”

“Why did you say ‘Chiswick’?” snaps Demeter.

At once I curse myself. Shit. Idiot. I’m losing concentration.

“Didn’t you say you work in Chiswick?” I answer as lightly as I can. “Summat like that?”

“No, I never mentioned it.” Demeter holds my wrist so tight that it hurts. “Who the hell are you?”

“I’m Katie!” I try to wriggle out of her grasp. “Now, let’s go and have a nice slap-up cream tea…or cake…jam tarts….”

“You’re hiding something.” Demeter gives me an angry wrench and I lose my footing.

“Aargh!” I land in the swamp and feel mud slapping onto my face. Oh my God, this is gross. I scramble into a sitting position, wipe my eyes, and glare at Demeter. All my self-control has gone. I feel as if my kite string has snapped; the kite is soaring away.

“Don’t you dare do that!” I slap swamp mud at her.

“Well, don’t you fucking dare!” Demeter slaps mud back at me. “I don’t know what you’re up to, but—”

“I’m not up to anything!”

I crawl to the side of the swamp and dip my head in the fresh water of the adjoining pond, trying to calm my adrenaline rush. OK. Regroup. This was not the plan. I have to keep it together. This may be Demeter, but she’s a guest too. I cannot be having a mud fight with her. I mean, it really wouldn’t sound good on TripAdvisor.

Although—who’s to believe her word against mine? You know. If it came to it.

Feeling steadier, I lift my head from the fresh water. My face is clean, all traces of mud gone. My baseball cap’s disappeared somewhere, but never mind. I pull my dripping hair back and scrunch it into a knot. Right. Back to my professional tour-leader act.

“OK.” I turn to Demeter. “Well. I think we should finish the nature walk there. I do apologize for any—”

“Wait,” she says, her voice suddenly quivering. “Wait right there. Cath.”

My stomach does a loop the loop of terror.

“No, Cat.” Demeter corrects herself, her eyes like gimlets. “Cat. Isn’t it?”

“Who’s Cat?” I manage to keep in control of my voice.

“Don’t give me that!” Demeter sounds so incandescent, I almost feel my skin shrivel. “Cat Brenner. It’s you, isn’t it? I can see it now.”

I’ve wrecked my disguise, I realize with a sickening thud. The hat and the makeup and the curly hair. All gone. How could I have been so stupid?

For a few petrified seconds, my mind gallops around my options. Deny…run away…other…

“OK, it’s me,” I say at last, trying to sound nonchalant. “I changed my nickname. Is that against the law?”

A crow flaps past, cawing, but neither of us moves. We’re both standing motionless in the swamp, covered in mud, staring at each other as though life is on pause. My blood is pulsing in terror, but I feel a strange relief too. At least now she’ll know. She’ll know.

Demeter has her swivelly-eyed, has-the-world-gone-mad look. She keeps peering at me, then frowning, then going all distant, as though she’s consulting her memory.

Things could go anywhere from here. Anywhere. I feel almost exhilarated.

“OK, I don’t understand,” says Demeter, and I can tell she’s trying to stay calm, with difficulty. “I don’t. I’m trying to understand, I’m trying to get my head round this, but I can’t. What the hell is going on?”

“Nothing’s going on.”

“You engineered me into the swamp!” Demeter’s starting to sound agitated. “You told me to hurry so I would fall in. Do you have something against me?”

She looks so ignorant, so oblivious, that I draw breath. Do I have something against her? Where do I start?

“And catching me with that stick!” she exclaims, before I can respond. “That was on purpose too. This whole morning has been a vendetta, hasn’t it? Has this whole week been a vendetta?” I can see her thoughts working, tracking back, analyzing everything, until her eyes snap with suspicion. “Oh my God. Is Vedari a real thing?”

“Of course it’s not a real bloody thing!” I explode with pent-up frustration. “Only a totally pretentious early adopter like you would fall for something like that. It’s pitiful! I just had to mention Gwyneth Paltrow and you were all over it!”

“But the website!”

“I know.” I nod with satisfaction. “Good, wasn’t it?”

I feel a shaft of triumph as I see her face dropping. Ha. Gotcha.

“I see,” says Demeter, in the same controlled, even tones. “So you’ve taken me for a fool. Well, congratulations, Cat, or Katie, or whatever you call yourself. But what I still don’t understand is, why? Is this because you lost your job? Are you blaming me for that? Because, one, that was not my fault personally, and, two, as I said to you at the time, losing your job is really not the end of the world.”

She draws herself up tall, despite the swamp, casting herself as the tolerant, put-upon boss figure, and my rage simmers up again into a froth.