Yes he did. Black Dog vanished and no one saw him go. All is quiet. His new owner, our neighbor, informed us yesterday that "he doesn't have a dog!"
Well, we thought so didn't we. A closer inspection of the backyards found Tunnels. Black Dog was a tunneler. He had Tunnels into all the backyards. Bingo,,,now we know. He didn't fly but tunneled his way,,,,away.