What I Learned: Chimerical - Things Learned while reading "The Hound of the Baskervilles"

"It was at my advice that Sir Charles was about to go to London. His heart was, I knew, affected, and the constant anxiety in which he lived, however chimerical the cause of it might be, was evidently having a serious effect upon his health.

–adjective

unreal; imaginary; visionary: a chimerical terrestrial paradise.