ere was a snap, a sudden, agonized cry, and Gabrielle was precipitated
to the bottom of the chasm. She fell heavily, extinguishing her candle
as she went, and rolling almost to the feet of Eric and Dorothy, who
were standing at the bottom of the chute looking upwards.

"Good gracious! What's happened? Gabrielle, are you hurt?" ejaculated
Percy, descending to the rescue with more haste than discretion, and
bending over the prostrate form of his sister. "Hold a light, Eric; I
can't see her face."

"Oh! Oh! I thought I was being killed!" gasped Gabrielle, raising
herself to a sitting position. "Give me your hand, Percy. Oh! Stop,
stop! My foot! I believe I've broken my ankle!"

The explorers stared at one another in blankest dismay. This was indeed
a predicament. What were they to do, buried in the depths of the earth,
and miles away from help of any kind?

"Are you sure it's broken, or could you manage to get up if we each took
your arm?" suggested Eric.

"No! No! Don't touch me! It's agony if I move."

"Better let me pull your boot off, quick!" said Dorothy, dropping on her
knees by the side of her friend.

It was a very different matter applying First Aid here from what it had
been at the ambulance class in the gymnasium at the College. Except
pocket-handkerchiefs, there were no materials of any kind to be had.
Splints were an impossibility. Dorothy bound up the foot as well as she
could, but her every touch was painful to her poor patient.

"You're sitting in such a wet place! Couldn't we lift you just a
little?" she suggested.

"No; please leave me alone. Never mind the wet."

Gabrielle's rosy cheeks had grown very white. She looked almost ready to
faint. The two boys turned to each other in desperation.

"We can't haul her up that chute with a broken ankle," said Percy. "I
must go back to the Hydro. for help, and you must stay with her. I'll be
as quick as I possibly can--I'll run all the way."

"Mind you don't tumble into any 'potholes', then," called Gabrielle
anxiously, as he scrambled up the chasm and departed.

Then began a long, weary vigil of many interminable hours. The candles
had burnt so low that the trio did not dare to have them all lighted
together, in case they should be left in the dark before assistance
came. They therefore used one at a time, and by its faint gleam the deep
shadows of the rocks appeared more dim and gloomy than ever.

"It's almost like being buried alive!" shivered G