"What?"

"Nothing." She resumes staring out of the window as the shuttle pod takes them from orbital station to surface. The windows are tinted, but the fire of re-entry is still bright enough to make her squint.

"Doesn't look like nothing," he says, scowling at her from his seat across the pod.

"I just-" She stops, wondering how best to phrase her unease. "Leaving the TARDIS behind. It's never a good idea, is it?"

"It's a sacred site. They want to control air traffic."

"I know, I know…"

"Look, if you want to go back−"

"I didn't say that." They both know she never will.

She scratches at the intricate design the Doctor has applied to the back of her hand absentmindedly. The same artwork adorns his left hand too, currently resting on his knee; bouncing up and down as he struggles to contain his enthusiasm for their latest adventure. "Try not to fiddle," he says.

"It is going to come off, isn't it?" she checks.

He glances down at his own tattoo. "Probably."

They land with a slight bump, curtailing their argument as the door hisses open on hydraulics. Three figures await their arrival, grey-robed, grouped on the edge of the landing pad. They are humanoid − two arms, two legs, one head − but that's where the similarity ends. They put Clara in mind of Cycladic statuary; sinuous limbs of worked alabaster; faces like pieces of carved jet atop improbably long necks.

Unperturbed by the dichromic giants, the Doctor steeples his fingers and bows his head; clearly a formal greeting. She hurriedly copies the gesture. The three aliens respond in kind.

"Welcome travellers," says the tallest of the three, voice high and soft. "We trust your journey was pleasant?"

"Uh, yeah. Fine thanks."

"I am Triptych Xae," continues the alien. "We are most grateful for your prompt response to our advertisement. How should we refer to you?"

"I'm the Doctor-"

"Doctor Spengler," she cuts in, "And I'm Doctor Venkman."

His mouth twitches violently, but he manages to bite down his reaction to her joke and maintain a professional veneer. He grabs her tattooed hand, a little more roughly than is strictly necessary, holding their matching designs up for approval. "Yes, and we're definitely bonded, look."

Triptych Xae nods, seemingly pleased. "The Church awaits," he says. He gestures with one sinuous arm to a pathway, cutting through the woodland surrounds.

"Well, we… um. Yes. We best get started. The Church has been cleared of all faithful, I assume?" the Doctor blusters.

"It is quite empty, we assure you."

"Good."

He picks up the enormous leather carpet bag he has bought along for the trip, for reasons as yet unexplained, and sets off down the path. She has to almost jog to keep up.

"What?" she asks, not quite able to keep the smile from her face.

"Doctor Spengler?"

"Hey, you're the one that woke me up to respond to an emergency-" Her fingers mime quotation marks around the word. "-that was actually a job advert for paranormal exterminators the TARDIS stumbled across."

"I get the reference," he replies irritably, "Ghostbusters, the original movie. Haha, very funny. But I'm clearly Venkman."

She stares at him, in genuine astonishment for a moment. "How can you possibly think that?"

"He's the good-looking, funny one," he continues, "And the leader."

"You are…" she huffs, "… trying my patience today, Doctor."

"I know," he grins, "It's more like we're actually married this way, isn't it? With the bickering."

She sighs, unable to frame an adequate reply. The Sixth Church of the Rangooth appears around the next corner; a welcome distraction. At least, she assumes it's the church. "Is this it?"

"Yep," he says, stopping to drop his bag and rootle around inside for various electronic components.

"Definitely Spengler," she mutters, turning her attention to the exquisitely carved columns of the front portico.

"Here, hold this." He hands her something that looks a bit like a miner's lamp, if Davy had been into more of a steam-punk aesthetic.

"What is it?"

"Our canary. Put it in the presence of a nearby pocket universe and it should sing. Well, flash and beep."

"You think there's another trapped time-traveller here? Like at Caliburn House?"

"What?" he snaps.

"Emma the psychic? Alien creature looking for his mate?"

He gives her a blank look. "Not ringing any bells."

"I guess not," she says, a little sadly. It's easy to forget, of course, that there's almost a thousand year gap for him between their adventures now and then.

He packs up his bag and they stroll towards the church steps. The air smells of pine and new growth, birds flitting between the vine-wrapped pillars. The overall impression is one of woodland idyll rather than paranormal mystery. It is hard to imagine any kind of ghost in the dappled sunlight.

"So, tell me Doctor. Why is it we have to be married to come here?"

"Well, the Rangooth are a very conservative people. The erotic carvings are seen as unsuitable for those who aren't bonded to look upon." He waves a hand at the wall art, which seems to show pairs and occasionally triplets of long-limbed and utterly androgynous figures, mostly holding hands or giving one another back rubs.

"Yeah, it's uh, graphic stuff."

He gives her a withering look. "Shut up."

"Whatever you say, Egon."