Of course, as with most forms of killing the hero that favor cruelty over efficiency, the hero manages to dig their way out, or a sidekick will pop out of the bushes and dig him up the moment the villain leaves. Often, however, it's just a matter of the villain being a sadistic prick. Now, it's payback time!') It could be a matter of security there's no murder weapon and you don't have to worry about disposing of the body, since, hey, you just did. ('37 years ago you stole my Froot Loops at recess. He might be righteously angry at the hero and is intent on making him suffer for past misdeeds. There's a wide range of reasons a bad guy does this. Regardless, the villain is going to kill the hero in one of the most appalling ways imaginable. If he's even more sadistic than usual, he may force them to dig the hole themselves. If the villain's a sporting sort of fellow, he'll provide a flashlight or an air canister. Sometimes, he'll tie the hero up before dumping them in the coffin. He's got something far worse planned: he's going to bury the hero. Does the bad guy shoot the good guy in the head? Cut his throat? Decapitate him? Stick them in an elaborate, above ground Death Trap? Nope.
