They're alive!
Researcher Robert E Cornish, with the help of a bunch of fox terriers named Lazarus, tried to raise the dead in 1930. And it worked.
He seesawed the canine corpses up and down to circulate the blood while injecting a mixture of adrenaline and anti-coagulants. Some came back to life and despite being brain damaged lived on for some months.
In 1947 he was ready to try this out on a human (using a heart-lung machine made from items including vacuum cleaner parts). A death row prisoner by the name of Alas Cornish volunteered but permission for the experiment was refused by the state.