Who is he?

Marco

When we got to the old apartments, we had no choice but to get off and take a look, we wouldn't know when we'd find whoever was throwing us out. The wall of the entire building was worn and vegetation was growing incessantly around the building, the entrance was a rusty, wide-open fence that left a patio full of undergrowth insight, as we entered the building we could hear the echo of our footsteps and give the vague feeling that at any moment the building would fall on us, we went up the rusty stairs checking each of the rooms, to see that there was no one.

—It's also clear —Leo says as he leaves a room.

—Do you think anyone's still living here? —Marco asks as he goes out into the hallway.

—We must always be alert, have you forgotten what happened to McCreery? —Leo responds as he turns to the entrance.

—All we need is the last floor —Marco says as he climbs the stairs.

—Let's hurry before he reaches us —Leo says as he follows Marco.