Name of a movie about secretive sect inside a pyramid?

I once saw a movie on television that I remember few details about. The only scene I recall was a man watching a cult performing a secret ceremony. I don't remember exactly, but I'm pretty sure it involved blood and death.

Anyway, the ceremony was inside a wood framed pyramid and the man was at the top, looking in, when the floor collapsed and he falls inside. I remember the men performing the ceremony were mad and possibly attacked, but that's it.

Thank you!

It could be "Young Sherlock Holmes" (1985), starring Nicholas Rowe, Alan Cox, Sophie Ward, Anthony Higgins, Susan Fleetwood and Freddie Jones.

From Wikipedia:
With the following of more clues, Sherlock Holmes eventually tracks down the killers to be Rathe, his present schoolmaster, and the school nurse, Mrs. Dribb. From the last survivor of Waxflatter's circle of friends, Holmes learns that the two are siblings of Anglo-Egyptian descent who were angry at the uncovering of the graves of five Egyptian princesses at the hands of the aforementioned wealthy men and the deaths of their parents in a resulting uprising, which was brutally thrown down by English troops. They vowed to kill off those responsible for disturbing the tombs and for their parents' deaths and performed the ceremony to "replace" the bodies of the princesses. So far, four girls were killed, leaving only one left.
By this time, Elizabeth has been captured and the same ceremony the trio witnessed earlier is being performed on her. Holmes and Watson manage to stop the ceremony part way through, and the pyramid and the Rame-tep are incinerated.
Wikipedia link:
http://en.wikipedia.org/wiki/Young_Sherl...

IMDB link:
http://www.imdb.com/title/tt0090357/

national treasure
there 1&2

MystMoonstruck is correct, it is Young Sherlock Holmes.