define end....it would not be the end of everything as energy would still exist, in whatever form, as such something would be present, so no ''nothing''
If end indicates the end of life...well life didnt start, on earth at least, for many years after the big bang, so perhaps it would be a pause, rather than an end, there is no way of knowing
energy is everything, it cannot be created, nor can it be destoyed(just change state), it has always been present, and always will be, it is the past, the present and the future, the beginning, middle and end, the core of all things that ever have or ever will exist