Immersive Ink

Naillus will quietly give warning to the group and prepare a wand of fire to the south.

Maloof, alerted by Naillus to something going on, rejoins the party.

Do you go into the gargoyle room to investigate, or stay in the hall?

Franklin draws his sword and stands near Nailus. If Nailus fires his wand then Franklin would, at that point, step forward so Nailus isn't standing in the front rank.

If we have time, the party could attempt to retreat around the corner to hide from sight (where Maloof was previously) and then Maloof could watch (invisibly) from the corridor to see what emerges into the gargoyle room.

That sounds like a decent plan. Naillus would agree with it,