Twenty-one years elapsed between the time Al Pacino and Robert De Niro first appeared in a movie together — The Godfather Part II, in which they never shared the screen — until they reunited. But the wait was well worth it. Michael Mann’s 1995 crime saga Heat, which opened 25 years ago on Dec. 15, 1995, was a taut and masterfully crafted cat-and-mouse thriller that found the acting titans in top form.