A thousand possibilities run through Skandi's mind, and he remains silent. Only one constant remains in each of them:
This is a trap.
The Sidereals are plotting something. They killed all the Solars, they killed some of the Lunars and drove the rest back. They could be using Firada as bait to lure Eris to her death. They could be 'arranging' for Firada to fall into the hands of the Realm so they could brainwash her as a weapon against her sister. This could be the first strike in a plan of attrition to wear the entire group down. The shield would do for Skandi; just claim he stole it. Zhou would be helpless without a Solar's political protection. Lauren/Sierra has no status in Yu-Shan; she'd be dead in minutes.
But he remains silent, because he knows that anything he could say would merely make the situation worse. Unless Eris is about to go charging off after her sister, Skandi's intervention will not help.