You should watch:

Descent: Part 1

This was episode number 26 of season 6.

The following characters appeared in this episode:

(as Brian J Cousins)Crosis
(as Professor Stephen Hawking)Himself
(as Natalija Nogulich) Admiral Alynna Nechayev
(uncredited) Ensign Gates
(uncredited) Ensign Jae
(uncredited) Ensign Kellogg
(voice) (uncredited) Enterprise Computer
Albert Einstein
Bosus
Captain Jean-Luc Picard
Counselor Deanna Troi
Commander Wiliam T Riker
Doctor Beverly Crusher
Isaac Newton
Lieutenant Worf
Lt Commander Data/Lore
Lt Commander Geordi La Forge
Tayar