Young Sherlock Holmes
I first heard about this film when I was in intermediate school (specifically, sixth grade, and I had only seen a snippet of it then), about a young Sherlock Holmes and Watson as they attend a boarding school in London and attempt to solve the mystery of an Egyptian cult specializing in hallucinogenic blowdarts responsible for driving their victims to suicide. Fairly enjoyable, and one of the earliest films to include a post-credits scene.