The story begins when Frank, the narrator, visits his friend Halpin Chalmers, author and occultist. Chalmers has the soul of a medieval ascetic, but reveres Einstein as a priest of transcendental mathematics. His wild theories about time and space strike Frank as theosophical rubbish. Chalmers has acquired a drug which he claims Lao Tze used to envision Tao. He means to combine those occult perceptions with his own mathematical knowledge, to travel back in time. Frank is against his friend taking the liao, but agrees to guard him and to note what he says under its influence...
