I think of Gotham on Fox -- which is about Bruce Wayne as a 'tween boy -- as "the loner show." As it boasts an ensemble cast, it follows many different story arcs about different characters, and most of the arcs explore what it means to be alone. Bruce Wayne and Edward Nygma (who will become the Riddler) are the more obvious loners, but "loner" applies to most of the main characters in their respective arcs. Each arc approaches the character's loner status from a different angle.
Edward Nygma most closely follows the stereotype that modern society has about loners. He is a huge nerd and is consistently rebuffed by his love interest. Bruce Wayne is very physically alone. As an autodidact, he spends most of his time alone trying to train himself in a new skill or investigating some pattern in what he sees on the news. Alfred the butler is his sole companion.
Selina Kyle, the street kid who will become Catwoman, also spends most of her time alone, believing that getting by as a homeless thief is the one way to maintain her independence. The interactions between Bruce and Selina, when they are both 'tweens, also shows the distinction between "loner" and "introvert." Introvert doesn't mean "always being alone" and extravert doesn't mean "always being with other people." Introverts feel more relaxed when alone and more drained by social interaction; extraverts are more bored when alone and more relaxed when interacting with someone else. Both Selina and Bruce spend a lot of time alone, but between the two, Selina is the more extraverted. Their interactions, so far, have consisted of Bruce doing something alone, and then Selina, seeking stimulation, interrupting Bruce to flirt. He feels ambivalent about this; he appreciates that someone shows an interest in what he does but he also prefers not to be distracted from his tasks. Selina Kyle, as depicted on this program, has been an extraverted loner.
The show also follows the respective narratives of Det. James Gordon (he is not commissioner) and the mafia lackey Oswald Cobblepot, who will become the Penguin. Gordon and Penguin are seldom physically alone. In most of their scenes, there are usually other people in the immediate vicinity, within at least a few feet from them. However, each of them is "psychologically alone" -- they are not well-understood or well-appreciated by the people around them.
Penguin is psychologically alone because of his secrecy. His only major concern is grabbing power for himself by ingratiating himself to those who have power, but he will betray anyone who's powerful if it means getting that power. He is loyal to no one but his mother. He is the most Peter Keating-ish of the characters on Gotham.
James Gordon is always surrounded by people, but, in his moral and psychological position, he stands alone. Except for being occasionally helped by assistant prosecutor Harvey Dent and his frequently unreliable partner Harvey Bullock, Gordon is almost completely independent in fighting against Gotham City Police Department's internal corruption. He is alone because he won't give in to the cynicism around him.
At one point, the Penguin mentions the contrast between he and Gordon, and it is the theme of the show. Penguin says to Gordon that they should work together, and he notices Gordon's revulsion at the idea. To that, Penguin asserts, "It's better to be with a friend in the dark than walk alone in the light." What Penguin means by this is that, if you're surrounded by corrupt people, it's better to join in their corruption than to stand alone against it. Gordon disagrees with that notion, and that is the idea that the show's events debates. Is it better to take the moral high ground even if you must be alone in doing so? In their contrasting examples, the story is a debate between the respective positions of Gordon and Penguin.
