Keller is friendly. Industrious. A bit lonely, sometimes. If it wasn't for the fact that he kills people for a living, he'd be just your average Joe. The inconvenient wife, the troublesome sports star, the greedy business partner, the vicious dog, he'll take care of them all, quietly and efficiently. If the price is right. Like the rest of us, Keller's starting to worry about his retirement. After all, he's not getting any younger. (His victims,...