"Protosilaus punched the Eighth necromancer--or rather, Septimus used him to punch the Eighth necromancer. Oktasiron was trying to summon the spirits of the Fifth."

This is probably even better evidence than, 'she keeps flirting with my cavalier'!

"It was ambiguous--Oktasiron appeared to have possibly hooked a bigger and more dangerous spirit than he intended, and it was having a deleterious effect on Septimus. But it was suspicious. And of course the creature demanded Protosilaus duel his cavalier for satisfaction, because the Eighth are always scrupulous about propriety when it's in their advantage to be."

This is unfair; the Eighth are scrupulous about propriety when it's in absolutely no one's advantage too.