“Impossible!” she exclaimed.
“I cannot be deceived!” said Doctor Spencer. “The attempt has been twice made. In each instance the dose was, fortunately, too small to be fatal.”
The slight nervous tremour that agitated Mrs. Calverley was not unnoticed by the doctor.
“This is a terrible accusation to make!” she said.
“But it can be easily substantiated,” he rejoined. “Indeed, it would be difficult to conceal the evidence of the crime!”
“On whom do your suspicions alight, doctor?” asked Mrs. Calverley, as firmly as she could. “On any one in attendance upon her?”
“One of them has been an unconscious instrument,” he replied. “But the hand that really provided the poison was elsewhere.”
After a short pause, he added, in a stern tone:
“Madam, yours is the hand by which the deed has been done!”
“Mine!” she exclaimed, fiercely and defiantly.