Sherlock Holmes in the 22nd Century (1999)

S1E12 The Musgrave Ritual

Title: The Musgrave Ritual Plot: The historic Musgrave sword vanishes from the tightly-secured museum, despite the fact that its inscription is easily accessible on souvenir replicas. Sherlock Holmes and Dr. Watson follow the clues to the Musgrave cemetery, ultimately venturing into the mysterious depths known as "the Abyss." The investigation unravels secrets long buried, revealing the true significance of the stolen artifact.