Supergirl's loneliness expands on Superman's darkest moment.

In 2025's Superman, the Man of Steel faces a dark night of the soul when he finds out that his Kryptonian parents sent him to Earth to rule over the planet. This information, which goes against everything Superman believed not only about his birth parents but himself as well, crushes him. But it isn't the thing that brings Superman to his breaking point.

That happens moments later when he realizes that Krypto, the goodest of good boys, has been taken. The only time Superman raises his voice in anger in the entire movie is when he confronts Lex Luthor, smashing into the billionaire's office screaming, "The dog, Luthor! You took the dog!"