Can I Reference Object Components from another Scene?

I am having a Object reference not set to an instance of an object, and i am guessing that is because i want to get values from a script that is attached to another gameobject that is not in the same scene...

I am trying to grabe the "score" variable from the "Game Scene" to the "Game Over Scene"

But somehow this is impossible for me... any suggestions?

I have tried everything I know, even creating a public reference for the gameobject in the inspector, but it wont let me attach it, (i guess because its in another scene, cuz it let me the objects in the same scene no questions asked)...