They had all been walking on again for some minutes when Donnington turned round.  “Take care, Bubbles!  It’s very slippery just here.”

“I’m all right,” she called back pettishly.  “Mind your own business, Bill.  I wish you wouldn’t keep looking round!”

Donnington saw Varick put out his right hand and grasp the girl’s arm firmly; but even so it struck him that they were both walking too near the edge on the side to the water.  Still, he didn’t feel he could say any more, and so he turned away, and again began trudging along by the silent Tapster’s side.

For a while nothing happened, and then all at once there occurred something which Donnington will never recall—­and that however long he may live—­without a sensation of unreasoning, retrospective horror welling up within him.

And yet it was only the sound—­the almost stuffless sound—­of a splash!  It was as if a lump of earth, becoming detached from the wet bank, had rolled over into the deep water.

At the same moment, or a fraction of a moment later, Varick laughed aloud; it was a discordant laugh, evidently at something Bubbles had just said, for Donnington heard the words, “Really, Bubbles!” uttered in a loud, remonstrating, and yet jovial voice.

And then, all at once, some instinct caused the young man to wheel sharply round, to see, a long way back from the others, Varick standing solitary on the brick path.

His companion had vanished.  It was as if the earth had swallowed her up.

“Where’s Bubbles?” shouted Donnington.

But Varick, still standing in the middle of the path, did not look as if he heard Donnington’s question.  The young man set off running towards him.

“What’s happened?” he cried fiercely.  “Where’s Bubbles, Varick?”

Varick was ashen; and he looked dazed—­utterly unlike his usual collected self.

“She stumbled—­and went over the side of the embankment.  She’s in the water, down there,” he said at last, in a hoarse, stifled voice.

Donnington turned quickly, and stared down into the grey water.  He could see nothing—­nothing!  He threw off his coat.

“Was it just here?”

He looked at Varick with a feeling of anguished exasperation; it was as if the horror and the shock had congealed the man’s mental faculties.

Suddenly Varick roused himself.

“Can you swim?” He gripped Donnington strongly by the arm.  “If not, it’s—­it’s no good your going in—­you’d only drown too.”

Donnington wrenched himself free from the other’s hold, and, rushing down the bank, threw himself into the icy cold water....

Suddenly he saw, a long way off, a small, shapeless, mass rising ... he swam towards it, and then he gave a sobbing gasp of relief.  It was Bubbles ...  Bubbles already unconscious; but of that he was vaguely glad, knowing that it would much simplify his task.

Very soon, although he was quite unaware of it, the affrighted, startled little crowd of people gathered together just above the place where he was painfully, slowly, swimming about, looking for a spot where he could try and effect a landing with his now heavy, inert burden.