Tom squinted as he tried to see through the holes in the ski mask. He could make out the large bag on the counter. The frightened woman who put it there now had both hands raised. As he took the bag off of the counter, Tom tipped an imaginary hat to the woman. The jest did not brighten her demeanor. Tom exited the first set of doors but stopped in the vestibule. Soon the windows of the building pulsated with blue and red lights. Tom hurriedly walked back into the building.

Incomplete question. The complete question reads;

Iggy squinted as he tried to see through the holes in the ski mask. He could make out the large bag on the counter. The frightened woman who put it there now had both hands raised. Iggy exited the first set of doors but stopped in the entryway. Soon the windows of the building pulsated with blue and red lights. Iggy hurriedly walked back into the building.

What is Iggy doing in the building?

He's robbing it.

Explanation:

Remember, we are told that "the frightened woman...had both hands raised" and that "the windows of the building pulsated with blue and red lights." Since the building was pulsating with blue and red light it indicates that the security alarm systems had been triggered.

Based on these circumstances, we could conclude that Iggy was robbing the building.

i think the answer would mist likely be an adjective clause, because unhappy is an adjective.