Lucretia mused over Gabriel's words and warning: "To be safe, you must
know all his secrets, or none." What was the secret which Dalibard had
not communicated to her?

She rose, stole up the cold, cheerless stairs, and ascended to the attic
which Dalibard had lately hired. It was locked; and she observed that
the lock was small,--so small that the key might be worn in a ring. She
descended, and entered her husband's usual cabinet, which adjoined the
sitting-room. All the books which the house contained were there,--a few
works on metaphysics, Spinoza in especial, the great Italian histories,
some volumes of statistics, many on physical and mechanical philosophy,
and one or two works of biography and memoirs. No light literature,--
that grace and flower of human culture, that best philosophy of all,
humanizing us with gentle art, making us wise through the humours,
elevated through the passions, tender in the affections of our kind. She
took out one of the volumes that seemed less arid than the rest, for she
was weary of her own thoughts, and began to read. To her surprise, the
first passage she opened was singularly interesting, though the title was
nothing more seductive than the "Life of a Physician of Padua in the
Sixteenth Century." It related to that singular epoch of terror in Italy
when some mysterious disease, varying in a thousand symptoms, baffled all
remedy, and long defied all conjecture,--a disease attacking chiefly the
heads of families, father and husband; rarely women. In one city, seven
hundred husbands perished, but not one wife! The disease was poison.
The hero of the memoir was one of the earlier discoverers of the true
cause of this household epidemic. He had been a chief authority in a
commission of inquiry. Startling were the details given in the work,--
the anecdotes, the histories, the astonishing craft brought daily to bear
on the victim, the wondrous perfidy of the subtle means, the variation of
the certain murder,--here swift as epilepsy, there slow and wasting as