The Attack (II)

Mark nodded with a smile. 'It seems like Steve is doing a good job on the other end. Now let's get to work.' looking at the window. 

Slowly opening the window, they peeked through the curtain and saw two people in the corridor. One was on the other side of the hallway while the other was walking away from them. Mark noticed the slightly opened door to a room on the right side. It was a classroom with benches attached and chairs to the side. 

He remained silent, observing the corridor and the two people in it while Kevin was looking out for people. As soon as the person on the other side walked away and the one walking almost in the middle, Mark jumped inside. He squeezed into the room on the right and turned around to see a person sleeping. Smiling at how convenient things are, he slit the man's throat.