I expect the pond will be empty by this time.”

I quailed with horror. If so, I should be discovered. I was tempted to turn tail: but that would be even worse. The only thing was to stay and see it through.

I confronted myself with the reflection that Dicky’s experiments so rarely succeeded, that in all probability the pistol still lay safe under four feet of water. If not—

“Hooray!” exclaimed Dicky, as we came in sight of the place; “it’s done the trick this time. See, Tom!”

I did see. In place of the water I left there in the morning was a large empty basin of mud, with a few large puddles of water lying at the bottom, and a few hillocks of mud denoting the places which had once been shallows.

My quick eye hurriedly took in the dismal landscape. For a moment my spirits rose, for I could nowhere discern the compromising object I dreaded to see. It was no doubt buried in the mud, and as safe as if the pond were full to the brim.

“Isn’t it ripping?” said Dicky. “It wasn’t easy to do, but it only wanted a little management. I mean to go in for engineer— Hullo, what’s that rummy stone out there? or is it a stone, or a fish, or— I say, Tom,” he added, clutching my arm, “I’m bothered if that’s not a pistol!”

My white face and chattering teeth made reply unnecessary. There, snugly perched on a little heap of stones, as if set up for inspection, lay the unlucky pistol, gleaming in the afternoon sun.

Dicky looked first at the pistol, then at me; and began slowly to take in the state of affairs.

He took a cautious step out in the mud in the direction of the weapon, but came back.

“I thought you could hardly be chucking in all those things for fun,” said he presently.

I stood gaping in an imbecile way, and said nothing.

“I know whose it is. He had it up here once before.”

“I say,” gulped I, “can’t you let the water in again?” Dick had not considered this. His triumph had been letting the water out. However, he would see what could be done.

We went down into the shrubbery. About a foot of water lay on the ground, promising great fertility some day, but decidedly muddy-looking to-day.

“The thing will be to bung up the hole first,” said Dicky.

So we set to work to hammer up the end of the zinc pipe and stuff the aperture round with sods and stones. I even sacrificed my cap to the good cause.

The bell began to ring before we had well completed the task. “That ought to keep any more from running out,” said Dicky. “If we’re lucky, the water will come in on its own hook at the other end.”

The theory was not exactly scientific, for scientific men do not believe in luck. Still, it was the best we could think of as we turned to go.

“Stop a bit,” said I, as we were leaving. “May as well tidy up a bit in there before we go, eh?”

“In there” was the bed of the pond.

“It might look better,” said Dick, turning up his trousers. We decently interred the pistol in the mud, and raised a small heap of stones to keep it down; and then cautiously obliterating our footsteps in the mud, we made for terra firma, and scuttled back to school as fast as our legs would carry us.

Fortunately we entered unobserved, and disencumbered ourselves of our muddy boots without attracting attention to their condition. Ten minutes later we were deep in our work in the big schoolroom.

Preparation that night was a solemn and gloomy ceremony. Dicky and I kept catching one another’s eyes, and then glancing on to where the Dux, cool as a cucumber, sat turning over the leaves of his lexicon.

“He’s got a cheek of his own, has Dux,” said I to myself.

“If I didn’t know it was him,” signalled the ungrammatical Dicky across the room, “I should never have believed it.”

“You may make as many faces as you like at young Brown,” glared Tempest at me, “but if I catch you making any more at me, your mother will need some extra pocket-handkerchiefs.”

“Jones,” observed Dr Plummer aloud, “a double poena for aggravated inattention.”

All right. I was getting pretty full up with engagements for one day, and began to think bed-time would be rather a relief.

It came at last. In the dormitory Ramsbottom successfully interfered with conversation by patrolling the chamber until the boys were asleep. No one doubted that he had been set to the task by the head master, and it augured rather badly for the resumption of the inquest next day.

However, even patrols go to sleep sometimes, and when I woke early next morning the usher had vanished to his own chamber. My first thought was not Hector, or the doctor, or my poenas, or the Dux, but the pond.

How, I wondered, was it getting on?

I routed up Dicky, and very quietly we dressed and slipped out. I knew that my early rising, if it were discovered, would probably be set down to my zeal for discharging impositions. But even they must wait now till we were sure about the pond.

For Dicky and I stood liable to as big a row as the assassin of Hector himself if anything went wrong with our experiment in engineering. Luckily very few fellows haunted this particularly muddy corner of the grounds, and now that Hector was above a daily bath, there was little chance of Plummer himself discovering the remarkably low tide on his premises—still less of his poking about among the stones in the bed of the pool.

To our great relief we found that our dam at the foot was holding out bravely, and that comparatively little water was trickling through the bank into the shrubbery. The flow at the upper end, however, was distressingly small, and though a whole night had passed we could still see the heap of stones under which the pistol was buried rising up from the shallow puddles around it, inviting investigation.

With astounding industry we worked away that morning, widening and deepening the little channel along which the rivulet made its way to the pond. And before we had done we had the satisfaction of seeing a fairly brisk inflow. We would fain have waited to see the fatal little island disappear below the surface. But the first bell was already an sounding when the water completed the circle, leaving it standing up more prominent than ever.

To our horror, at this precise moment Tempest strolled down.

“Hullo! what are you two after? Fishing? One way to catch them, letting all the water out.”

“It was an experiment,” said Dicky, who, like myself, was very pale as he looked first at the Dux, then at the guilty hillock in the pond.

“So it seems. In other words, you’re making a jolly mess, and are enjoying yourselves. I hope you’ll enjoy it equally, both of you, when Plummer sees what you’ve done.”

“Shall you tell him?” I asked, somewhat breathlessly. The Dux laughed scornfully.

“You deserve a hiding for asking such a thing. Come here! Jump out on to that little island there, and stay there till I tell you.”

“Oh, Dux, please not,” said I, in a tone of terror, which was quite out of proportion to the penalty. The pistol was only two inches below the surface!

“Do you hear? Look sharp, or I’ll chuck you there.”

That might be worse. It might hurt me and cut up the soil. So I jumped gingerly out, and stood poised with a foot in the water on either side, dreading at any moment to see the stones slip and the tell-tale gleam of the buried weapon.

“If you don’t stand properly,” said the Dux, “I’ll make you sit down. Come along, young Brown, it’s time we went up to school.”

“How long am I to stay, please?” I inquired.

“Till you’re in water up to the knees,” said the Dux, as he turned away, with the faithless Dicky beside him.

Up to the knees! I stood loyally for five minutes, during which the water gained about an eighth of an inch up my ankles. Then the second bell rang,