I had had so many reasons to believe in my friend's subtle powers of reasoning and extraordinary energy in action that I felt that he must have some solid grounds for the assured and easy demeanour with which he treated the singular mystery which he had been called upon to fathom.
Tenía tantas razones para confiar en las penetrantes dotes deductivas y en la extraordinaria energía de mi amigo, que supuse que debía existir una base sólida para la tranquila y segura desenvoltura con que trataba el singular misterio que se le había llamado a sondear.