Story involving children mind-controlled using food to take care of magical creatures after dark

Question

I'm trying to recall a story from my childhood. I believe this was an episode of a TV show, but could possibly have been a short film. I saw this in English in the mid-1990's.

The story involved some modern children (I think two brothers) who arrive at a somewhat Victorian-looking boarding school or orphanage. At the institution, the children are all served a very bland-looking gray mush at lunch. It turns out that this food contains some sort of drug that makes the children susceptible to mind control. After the children have returned to their bedrooms for sleep, the school administrators play some musical notes over the public address system to summon the children down to a subterranean level where they spend several hours each night taking care of dragons or other fantasy creatures being raised, possibly as part of some plan to take over the world. The plot is discovered because one of the new boys decides that the gray food is disgusting and never has any, so he is unaffected by the mind control efforts. He notices the unusual behavior of the other children, pretends to be mind controlled himself while following them underground, and destroys the baby creatures being raised in a fairly quick showdown.

I was reminded very much of this story when I read H. P. Lovecraft's short story The Festival as an adult, in which a protagonist is led underground to meet eldritch abominations, but the details don't match - Lovecraft's story doesn't involve a mind-control drug, and the underground area is underneath a church rather than an educational institution.

Answer 1

This is "The Tale of the Hatchling", episode 12 of the second season of the original Are You Afraid of the Dark? show.

.... A vehicle pulls through the gates of a boarding school called "The Black Brook School" supposedly one of the best boarding schools around. Mr. and Mrs. Wilson who had to go away on business for six months thought it was the best place for their children, Augie and Jasmine "Jazz" to at stay for the time being. Both of their parents seemed to find the place interesting. Then they went into the school to find the Headmasters Mr and Mrs. Taylor and to register.

....

Jazz tells Augie she doesn't want to stay there, because she has a weird feeling about the place. Augie tells her they have no choice because their mom and dad can't take them with them. Although Jazz wants to try and fight her way out of the school, Augie persuades Jazz to stay and give it a chance. Then they parents leave, saying they'll visit in about a month. That night at supper time, a big bowl of what looks like rice pudding is passed along to each student sitting down at the table. Then they meet a classmate named Kit, Kit tells them that every night for dessert they're served that same dessert and it's called Sponge with a U calling it Spunge and it's really good, but still neither Jazz nor Augie try it.

....

All of their classmates were climbing down the ladders and sprinkling some sort of unknown powder onto something in the pool. Jazz tried speaking to Marie and a few others but none of them would answer. Jazz then found out the the pool was full of hundred of giant foot ball sized eggs. The question was what really going on in this school? Augie figured that they were all in trance knowing exactly what to do and nothing could stop them. When they realized that Mr. and Mrs. Taylor were nearby, they decided to play along sprinkling the powder onto eggs....