Frank explained, and the doctor listened attentively to his story.
"This is worth investigating," he declared. "I know a few of the tricks of these fellows, and I think I'll find out what was done to your horse, if anything was done."
The boys watched the doctor with great interest. They saw him examine the lame leg from the knee down. In doing this he put on a pair of spectacles.
Nemo was nervous. He seemed afraid the doctor would hurt him, and it was not found easy to make him stand.
At last Dr. Cobb uttered a sharp exclamation.
"Bring my case, which you will find under the seat in my carriage, Grody," he directed.
Grody hastened to obey.
"Have you found out what the matter is, doctor?" Frank anxiously asked.
"I believe so, but I am not sure yet."