Compiled some material (with spoilers for below-mentioned ESes and Heart’s Desire) on intriguing possible interconnection of October and the Red-Handed Queen. With the Queen of Air and Darkness as "her avatar in London" (whose factions at Hallowmas were Revolutionaries and the Great Game, to boot; to say nothing of the outright "Red-Handed" in her Order’s name and all their mirrors and chess).
(What a character. I simply couldn’t resist looking into. Charismatic and strong woman, succesfully daring to outwit an oppressor with such a karmic flavour. And I adore these decadent parties of the Order.)
It’s also interesting that "The Shallows", featuring October, and "The Heretic of Hollow Street", featuring the Queen, followed each other in August and September 2019, the Queen of Air and Darkness first appeared in October 2019, and simultaneously it was just the time to outline plans for the finale of Heart’s Desire (the first half of 2020).
I’ve seen Carrywell mentioned as another candidate, but she is in Tomb-Colonies instead of London where the Queen’s avatar is said to be, isn’t connected to Parabola and, most importantly, isn’t recognized by Nemesis players when unmasked after Hallowmas.
But actually, I don’t discard a possibility that the Red-Handed Queen might be even several people at once – as a shared dream or a symbol of a position in the Great Game.