You should watch:

The Host

This was episode number 23 of season 4.

The following characters appeared in this episode:

(uncredited)Lathal Bine

(uncredited) Ensign Jae

(voice) (uncredited) Enterprise Computer

Captain Jean-Luc Picard

Counselor Deanna Troi

Commander Wiliam T Riker/Odan

Doctor Beverly Crusher

Governor Leka Trion

Kalin Trose

Kareel Odan

Lieutenant Worf

Lt Commander Data

Lt Commander Geordi La Forge

Nurse Alyssa Ogawa

Odan