ADJ.
infernal
VERB + BATSQUEAK
feeling
BATSQUEAK + NOUN
insanity
noun
The ultrasonic noise emitted by a bat, especially as used for echolocation.
A faint echo (of something); a tiny pulse, a slight wave (of feeling, emotion etc.).
Gómez Arias, like don Álvaro, dies without our feeling a batsqueak of regret because neither is given any redeeming features.
The first infernal batsqueak of insanity was making itself heard in a new generation.