You should watch:

The Nth Degree

This was episode number 19 of season 4.

The following characters appeared in this episode:

(uncredited) Ensign Jae

(voice) (uncredited) Enterprise Computer

Albert Einstein

Barclay

Captain Jean-Luc Picard

Counselor Deanna Troi

Commander Wiliam T Riker

Cytherian

Doctor Beverly Crusher

Ensign April Anaya

Ensign Brower

Lieutenant Worf

Lt Commander Data

Lt Linda Larson

Lt Commander Geordi La Forge