S3. EP.27: It is the day of Tai-San's ordination as the New Supreme Mother. Despite her dream warning of a probable assassination attempt on the Guardian, and Luke's recommendation that the ceremony should therefore be held in private, the Guardian has overruled their concerns. As the ceremony gets underway Tai-San spots Lex on a nearby rooftop about to fire a crossbow. She steps in front of the Guardian and takes the hit. The ceremony ends in chaos and panic, though mercifully Tai-San is only slightly wounded.
 
Note the two ceremonial chairs behind the Guardian.
The chairs appear again inside the Mall in Ep.29 after Pride and May have escaped taking Brady with them; the Guardian has called in the Praetorian Guards. The Guardian and Tai-San are to preside over Luke's trial.
In Ep.32 the Guardian has set in motion his plan to blow up the Mall and everyone in it. The rebels surround the Mall and as luck would have it, Alice and Ned have hacked a hole in the basement wall just large enough for KC. He tells Bray of a cunning plan.
 
But hey! There's those two chairs again, (I can certainly see one of them), left there after the chaos of the attempted assassination of the Guardian. Oh, but weren't they (both) taken inside for Luke's trial?
So where are these chairs from? They aren't your average meeting hall chair. The inscription reads "AOF". That's Ancient Order of Foresters. They're like a cross between an insurance company and a charity.