ironically eliminating it altogether can put you in a state of suspended animation. and to do that, roth gave the creatures a dose of toxic gas, hydrogen sulfide, truth as strange as fiction. what's your favorite movie? >> "the princess bride." >> he is almost dead or a little dead. >> right. i love that. >> i've seen worse. >> well, it just so happens that your friend here is only mostly dead. >> what ends up happening is creatures don't move. they actually appear dead, only they're not. >> with backing from the military, roth decided to try his experiment on mice. take a look here. here's the mouse getting a dose of toxic hydrogen sulfide. now, a normal mouse would just be a ball of activity. not this one. he isn't sleeping. he isn't dead. it's just that every process in his body, even death, is in slow-motion. when i came to visit, roth showed me how he did it. >> what you're doing here is you're just dimming the metabolism. just dimming the light a bit.