Beagles. Hmmm. They can be busy headed and robust enough to engineer their own escape routes,
I've had 2 Xbreeds over the years and they were great dogs but I spent far too much time looking for them after they had burrowed, chewed or climbed their way out of the yard the minute they were left alone. Even if they had other canine company.
I could not figure out how one was getting out until I did some stealth surveillance and watched him wedge himself between the house and the side fence, wriggle upwards until he could stand on the fence, get onto the veranda trot to the front of the house, jump onto the wheelie bin and then swagger off to raid the garbage at the chicken shop a couple of blocks away. How the hell did he figure that out, no one taught him? There is a reason they are so sought after as customs dogs, no lack of drive and imagination.
The Hound is far too dumb and inflexible to devise any complex strategies and any more than 5 minutes intense concentration wipes her out for 8 hours. If she ever realises she can get just jump a fence, there will be trouble.