Adam could hear a blaring alarm as the speakers began to wail sirens.
"The building has entered a state of lockdown and nobody can leave or enter" repeated the speakers.
[They must be planning to trap in the thieves and wipe them out before they can get external assistance and they must have dozens of guards that are armed within the building] observed Adam.
[The thieves can't be that stupid and must know that there will be reinforcements coming from around the building] thought Adam to himself, confused by the plan of the thieves.
The building they had entered, from what Adam had seen, had a hollow centre where there was the stage and the Auction House, with the area around it being viewing rooms that went up the floors.
So, unless the thieves were able somehow blocking off the hollow centre, that had the valuables and not that many guards, it would be impossible for the thieves to pull off the robbery and get away.