You weren't even home when Riley got out, so it's pointless to blame yourself. Save your energy; you'll need it when Riley comes back and you hug him like mad. (Then throttle him. LOL) My RB Boo got out once and it just happened to be the coldest day of the year and snow was really piled high. My son and I searched and searched, thinking that we'd easily be able to see a midnight black cat against white snow. Not a chance. I cried and cried and made my son miserable. That night I left the garage door open a few inches and at approximately midnight I heard Boo's meow. I ran out to the garage and there he was by the door, ready to come in where it was safe and warm. He was covered w/mud; I have no idea where his adventure took him but apparently it was far and long enough. He was gone for nearly 24 hours. Just trust that Riley will come home. Keep the faythe.