"I pray to Heaven you will not undertake this experiment alone, will you?"
"Oh dear, no; not alone."
"You will take a companion with good nerves, and reliable in case of disaster, won't you?"
"I shall bring two companions," the doctor said.
"Ah, that's better. I feel easier. I am sure you must have among your acquaintances men who—"
"I shall not think of bringing men, Mr. Pender."
The other looked up sharply.
"No, or women either; or children."
"I don't understand. Who will you bring, then?"
"Animals," explained the doctor, unable to prevent a smile at his companion's expression of surprise—"two animals, a cat and a dog."