So, the show's main characters are Alice and Bob and their circle friends. Maybe they get into wacky situations, maybe They Fight Crime
, maybe they run their own small business, whatever. Occasionally, every couple of episodes, Alice or Bob, or one of their friends, find themselves at the check out at the local grocery store, where they sometimes chat fondly with the cashier, and get some convenient insight into their trouble of the week through his quirky stories, that always somehow manage to relate to their issue. Of course, a few seasons of the show go buy and locally quirky cashier gets...*gasp*
continuity. Maybe back in season one he encourage Alice to get together with Bob by relating his own story about his wife, and when he pops up back again latter he mentions that she's pregnant, and their happy together, then maybe a season or two latter that his little tyke is learning to finger paint, and then even further along that said child is starting pursue a serious painting career, maybe he regales Bob with stories of his martial troubles (that erriely mirror his own with Alice) and how they slowly resolve, or get worse.
The thing about the D Plot is that it's little more then a background thing that shows up, not even in every episode, sometimes it's barely even a running gag. But it has it's own internal continuity, it grows and changes like the rest of the story, if almost entirely off screen. It's not a Brick Joke
- because there's not set up and no payoff- it's just a background character and his funny stories or life that occasionally intercept, but never really come into play with one another. Entire years can go by before their's a development in the D-Plot, but it's still there, just not involved at all with the main characters.
- In How I Met Your Mother we saw Straut marry the love of his life Claudia, battle alcoholism, and have a daughter, all with less then 50 lines.