Let's talk about death.
Let's go way back to my least favorite folks from antiquity: the Egyptians.
They had some strange ways of dealing with death. First of all, they figured there was an afterlife. Some of the lucky ones got mummified. Their guts and parts likely to rot were removed, jarred like we can tomatoes in August, and stuff was put into the empty cavity to dry out the flesh so it didn't rot.
Their belief was, this shell of a person, minus brain, even, would ascend on a big boat to someplace above and they'd have another cool existence there.
It got even better for pharaohs and queens. While their guts and bits were removed and jarred, they had huge tombs dug in the sand and/or (if they were really lucky) they already had tombs constructed while they were alive...you know them as pyramids.
They had their slaves killed and slipped into the tombs to care for them in the afterlife. Their cats bought it, too. Their gold, their riches, all slipped into the sarcophagus with their mummified bodies for people to dig up later.
Oh. Yeah. About that later stuff. The kings and such who had tombs constructed by slaves over their lifetimes made sure nobody could find the way out after their bodies were put down. Everybody who worked on the construction, who knew the secret passages to get out while building...they got offed and buried along with the main corpse.
Neat. All at once. Good-bye everybody!
Now, I want you all to go back and view Karloff's original The Mummy.