The coal-dispensing station looked like a massive cauldron, with holes plus anchor points at various junctures, like a strawberry pot. They were hailed the moment it became clear they were in need of fuel and directed into one vent by the gesticulations of a precariously stationed native boy.

Spoo supervised as they let out the lines to a group of eager local sooties whose hands reached out from the cauldron interior in an eerie disembodied manner. Like a poltergeist.

Anitra undertook a rapid haggle over cost.

Primrose, as ship’s purser, stood by wearing a deeply contemplative expression more common when deciding how to dress for a ball.

For a price that Prim deemed just shy of extortionist, a tube was ejected outward and connected to the open porthole of The Spotted Custard’s boiler room. Coal was transferred aboard and gold transferred off. Transaction complete, they were gestured rudely away by the disembodied hands.

Rue directed Percy to moor far out over the rapids, at the most isolated island.

She still felt their position exposed. True, there were white-water rapids between them and shore, but there were also rope bridges aplenty and small light aircraft developed exactly to deal with the difficulty inherent in living near cataracts.

“I don’t like this, Lady Captain. We’re awfully easy to board.”

“Agreed, Spoo. But what can we do? We need water and this is the only way to take it on.”

Tasherit joined them, leaning over the forecastle rail.

“Not a particularly defensible military position.” Her attitude was deceptively casual.

“Nevertheless,” said Rue, “I’m afraid you must guard us against attack.” She looked down at her small shadow. “No shore leave, Spoo. Apologies.”

“Understood, Lady Captain.”

Quesnel appeared.

“Must everyone come up top right now when we are at our most vulnerable?” Rue asked the world at large.

“Got to supervise the water coming in, Lady Captain. It’s not easy to draw off rapids.”

“Fine. Just please be careful.”

“Didn’t think you cared.”

Rue glared.

Quesnel glared back.

“Softly, you two.” Miss Sekhmet was the only one brave enough to modulate the crackling friction between captain and chief engineer.

Rue considered Spoo’s finer feelings and relented by walking away.

Miss Sekhmet strode the deck, stationing armed deckhands and decklings at various points, including up the sides of the balloon in lookout positions. She kept her own pistol at the ready. Spoo and Virgil manned the Gatling gun, although they were under orders not to use it in port unless given a direct command. Meanwhile, Quesnel, with Anitra on his arm, oversaw the sooties as they telescoped the hydrology tube down to sink into the rapids. It took seven tries to find a point deep enough not to break the pumps with too much air intake.

Rue carried her Parasol-of-Another-Colour open against the sun – it was greenish today – reassured in the knowledge of its armament. Acid was effective on everyone, and she wore goggles on her hat to pull down upon emission. She’d refilled its complement of lapis lunearis, lapis solaris, and lemon and basil tincture from the ship’s medical cabinet. Thank goodness Primrose kept that fully stocked. She’d ensured the parasol’s remaining four numbing darts were loaded. It occurred to her that, if necessary, the lemon and basil tincture might be added to barley water, improving taste and mood in one dose. The idea put a spring in her step.

Primrose wanted to leave The Spotted Custard in search of a marketplace.

“Absolutely not.” Rue twirled her hideous parasol in frustration.

“But, Rue, we’ll run out of food eventually.”

“How soon is eventually?”

“Well, three weeks. But we’ve no milk at all.”

“Too hot for tea anyway.”

“You aren’t being reasonable. I’ll be safe.”

“No, Prim, I can’t spare the manpower to guard you if we don’t need stores that badly.”

“Tell that to Cook.”

“You tell it to Cook. Needs must.”

“I hate it when you say that. You sound like your mother.”

“Don’t be cruel. Now go below, please. And take your brother with you.”

Primrose sulked but did as Rue asked. “Come along, Percy. I’m sure there is something you need to research and we should keep an eye on Footnote.”

Percy was remarkably docile. “Indubitably. I was wondering about desert fauna and the relative frequency of sand fleas only yesterday.”

Rue was suspicious. She had long since realised Percy only got publicly pedantic about his studies when he was trying to cover something up. His emotions. Or his real interest. Or his activities. Or some less savoury research.

Perhaps it was because they were so very prepared.

Or perhaps their mysterious enemies hadn’t any contacts in Wady Halfeh.

Or perhaps the town was simply too wrapped up in its own business.

But no attack came.

The Custard was able to set back out only a few hours later in relative harmony.

Everyone stayed tense, though. A gaggle of off-duty decklings remained glued to the aft railing, scanning the northern skies beyond their Drifter escort for hunters to reappear.

Perhaps the enemy’s repairs took longer than estimated. Or perhaps the Custard’s refuelling in record time gave them a consistent lead, but no one else broke the skies. They had the whole world to themselves as they left Wady Halfeh far behind and headed into the desert. The Nile disappeared. The moon rose into the sky, and below them was nothing but rolling sands and the jagged shadows of craggy rocks.