International Magical Trading Standards Body - Igor Karkaroff
These offices are very familiar to Igor, because in the 1970's he worked in the Russian Wizarding Embassy and had to come to this level, often.
MASKED, with a spell cast upon himself to alter the sound of his voice (his accent may give himself away), he bursts into the office to find an elderly janitor using his wand to empty the rubbish baskets. He's startled to see the Death Eater, but before he can do anything else, Igor disarms the janitor who then expects to be killed.
But Igor remembers the man from way back, even though he can't recognize Igor through the mask. Igor shouts at the janitor to, "Get out of here or you'll be killed. The place is under attack!"
The janitor then flees out of the room... whether or not he survives is another story.
Igor then goes on to another office to see if he can help the others on this level.