No it wont get everyone from where you are standing currently. Info on Close Blasts;
Blast: A blast fills an area adjacent to you that is a
specified number of squares on a side. For example,
the wizard power thunderwave is a blast 3, which
means the power affects a 3-square-by-3-square area
adjacent to you. The blast must be adjacent to its origin
square, which is a square in your space. The origin
square is not affected by the blast. A blast affects a
target only if the target is in the blast’s area and if there
is line of effect from the origin square to the target.
It may work on everyone except the NPC if you made it to F5.