Question

One night—it was on the twentieth of March, 1888—I was returning from a journeyto a patient (for I had now returned to civil practice), when my way led me through Baker Street. As I passed the well-remembered door, which must always be associated in my mind with my wooing, and with the dark incidents of the Study in Scarlet, I was seized with a keen desire to see Holmes again, and to know how he was employing his extraordinary powers.

Which of the bolded words in the excerpt is a temporal transition?

One night
keen desire
through Baker Street
dark incidents