... by an Earthquake
A hears by chance a familiar name, and the name involves a riddle of the past.
B, in love with A, receives an unsigned letter in which the writer states that she is the mistress of A and begs B not to take him away from her.
B, compelled by circumstances to be a companion of A in an isolated place, alters her rosy views of love and marriage when she discovers, through A, the selfishness of men.
A, an intruder in a strange house, is discovered; he flees through the nearest door into a windowless closet and is trapped by a spring lock.