Complex sentence: In 1942, Emma and Scott encounter the fantasy book entitled, "Through the Looking-Glass," and identify in the words of Lewis Carroll's "Jabberwocky" the missing element of a time-space equation enabling them to travel to the alien destination.
Split into simpler sentences: In 1942, Emma and Scott encounter Carroll's fantasy book "Through the Looking-Glass", containing the poem "Jabberwocky". In its words they identify the missing element of a time-space equation enabling them to travel to the alien destination.