Doctor Who (Doctor Who) (2005) (№ 361681)

The only psychopaths in the Universe who kill you nicely - no blood, no screams. They just toss you back and allow you to live to death. The rest of my life goes by in the blink of an eye, you die in the past and in the present they take the energy of the days that you could live, steal them. Abstract creatures live at the expense of potential energy.