Sentence:  Suddenly a treble auto horn tootley-toot-tootled , and , thumbing hopefully , I saw emergent in windshield <WSD>flash</WSD> : red lips , streaming silk of blonde hair and - ah , trembling confusion of hope , apprehension , despair - the leering face of old Herry . 
Meaning of the word marked with <WSD> tags:  a momentary brightness