The analyses of a clause

The protagonist is prince of Amber, has amnesia, but tries to conceal the fact, staying at the house of one, Flona, of his sisters. Now, his brother, Random comes to her house running from unknown enemies, and they also comes to her house after him.

I felt a hack-raising vibration, in the vicinity of my eardrums. I knew, in that moment, that Flona had blown her whistle. When I heard a window break, somewhere off to my right, I was not surprised to hear a growled rumbling and some baying, somewhere off to my left.
"She's called her dogs," I said, "six mean and vicious brutes, which could under other circumstances be after us."
[Nine Princes in Amber" of The Great Book of Amber by Roger Zelazny]
I'd like to know if "under other circumstance" means "if it were under other circumstances" and "be" means "go."
Thank you in advance for your help.