What band is this?

I been trying really hard to name this band. The only thing I can describe is the music video, so here it goes.

It starts off with a guy finding this backpack. He looks inside and starts walking away. As he's walking people start to notice a follow him, to the point they start to chase him. I remember him going threw a building where the band is playing. He gets to an open door and the singer is there stares at him and closes the door. He ends up going through a grocery store too, just don't remember when. Well he eventually ends up on the roof where he drops the backpack and someone ends up picking it up again. That's how the video ends.

Hope someone can help me, it's been bothering me for a while.

Thank you!