Moriarty was the Napoleon of crime so Fu Ch'ing is its Genghis Khan. (p. 144)
Ginny dons a cloak that is:
"...a minor talisman; Fritz Leiber had once played Prospero in it." (p. 145)
Here we have:
a reference to another fantasy and sf writer;
a reference to Shakespeare's A Midsummer Night's Dream;
by extension, also a reference to Anderson's A Midsummer Tempest;
a reminder that, in this fictional universe, talismans have real power;
a reference, I suspect, to a real cloak owned by the Andersons?
Her owl pin is "...much more potent..." (ibid.) not only because it is the badge of her order but also because it has been to Hell. Although this "Hell" is a planet in another universe, not a supernatural realm, it is somehow connected with magic/goetics. A "demon"/denizen of Hell hears and implements a curse and the demons serve the Adversary.
How does "goetics" work? Anderson makes it sound like an extension of known science:
"'...goetic quantum-wave transference across a potential difference...'" (p. 99)
- is an energy source like fuel or a waterfall and, like them, is conserved. When a scryotronic communicator malfunctions, it is thought that it has:
"...gone into wave-mechanical oscillations, jumps to and fro between alternate histories..." (p. 114)
The apparatus for testing this idea involves mandrakes, described as "...cantankerous buggers." (ibid.)
Go and catch a falling star,
Get with child a mandrake root,
Tell me where all past years are,
Or who cleft the devil's foot,
Teach me to hear mermaids singing,
Or to keep off envy's stinging,
What windServes to advance an honest mind.
-copied from here.
Neil Gaiman quotes Donne's poem at the beginning of Stardust.