The building buzzed with noise,--swift footsteps echoed on the stone floors, snappy talk broke out with the opening of every door, bells tinkled, elevators hummed,--no wonder they did not hear me knock.

But I noticed that other people went in without knocking, so after a while I did the same.
There were several men and two women in the small, brightly lighted room.

They were all busy.

It was very confusing.

Should I say "Sir" to the roomful?
"Excuse me, sir," I began.