Diarmuid doesn't notice the light until he sees Bucky starting at it. When he does see it, though, he can't help but frown. He might not know what it is, but Lord James doesn't seem happy about it, so it is probably not a good thing.

He follows Bucky over to the pedestal and then digs in his bag until he finds the fire key. However, he doesn't look for where he should put his key right away. Instead, he holds it close to his chest. He will wait until everyone is together and putting their keys in just in case something happens before they are all ready...