Episode 271: "Genesis" 

Dr. Crusher prepares a synthetic T-cell for Barclay, the Enterprise's resident hypochondriac, who has come down with a flu for which he has no immunity. Meanwhile, Data gets ready for the impending birth of Spot's kittens, and Nurse Ogawa announces that she is about to become a mother herself. Worf uses the time to test the ship's weapon upgrades, and is upset when one of his torpedoes veers off course. This affords a slightly bored Picard an opportunity to retrieve the missile, and he takes Data with him. Soon after the pair leaves, Worf begins to act increasingly irritable, demonstrating signs of primordial behavior.
Other members of the crew soon begin to exhibit strange symptoms. Barclay becomes more energetic, Troi feels cold, and Riker loses his ability to think. The dramatic changes also continue in Worf, who tracks Troi to her bathtub and tries to force himself on her. When she refuses, he bites her cheek, and they both wind up in Sickbay. There, Worf becomes completely unresponsive until Beverly discovers a venom pouch in his neck. He sprays Beverly with the acidic poison, then disappears into the bowels of the vessel. It is soon discovered that he has been doing this all over the ship. Continuing to investigate, the staff learns that incidents of behavioral changes are occurring all over the Enterprise. However, when Riker tries to alert Starfleet, he is unable to concentrate enough to do so.

Returning to the Enterprise, Picard and Data are surprised when they find the ship adrift in space. They are even more shocked when they board to find computers down, systems off-line, and eerie, animal-like sounds permeating the ship. They find Troi in her quarters, in the process of transforming into some sort of amphibian, and Data discovers that her DNA has been altered, causing her cells to mutate. They proceed to the Bridge, where they find Riker, who has changed into a prehistoric man. Data learns that the entire crew is affected and concludes that the Enterprise's population is de-evolving.

Data explains that a synthetic T-cell has infected the crew and activated their introns ódormant genetic codes held over from earlier evolutionary times. He also points out that Picard has been infected, which gives them only a few hours to get the ship functioning and solve the problem. They return to Data's quarters to work, and notice that while Spot has changed into an iguana, her kittens, who were born in Data's absence, are fine. Realizing something in Spot's womb protected her babies, they track down the transformed Nurse Ogawa and find that her embryo is unaffected because of a similar protective substance in her womb. However, as they prepare to access her amniotic fluid to develop a retro-virus, Picard becomes increasingly nervous, a sign of his impending transformation. Then a huge, terrifying creature pounds outside the locked door, and they realize it is Worf.

Deducing that Worf has come to mate with Troi, who has a Klingon bite on her cheek, they determine that the only way to lure away Worf is to duplicate her pheromones. Since Data must continue developing the retro-virus, Picard, who is beginning to transform, must spread the pheromones himself. He gets Worf's attention by spraying them into the corridor, and the giant creature is soon chasing Picard through the ship. Worf soon realizes he has been fooled, then corners the captain. Thinking quickly, Picard Is able to use a power cable to shock Worf, knocking him unconscious. Data completes the retro-virus, and the crew Is restored to normal. Beverly realizes the virus was created when she used the synthetic T-cell to fight Barclay's flu, and names the strange affliction that plagued the crew after her hypochondriac patient.

Production: 271
Season: 7 Episode: 19
Air Date: 03.21.1994
Stardate: 47653.2
Patrick Stewart as Jean-Luc Picard
Jonathan Frakes as William Riker
Brent Spiner as Data
LeVar Burton as Geordi La Forge
Michael Dorn as Worf
Gates McFadden as Beverly Crusher
Marina Sirtis as Deanna Troi
Patti Yasutake as Nurse Ogawa
Dwight Schultz as Reginald Barclay
Memorable Quote:


Dr. Crusher: [about Lt. Barklay] This morning he de-evolved into a spider and now he has a disease named after him.
Counselor Troi: Well, then, I think I should clear my calendar.

Click this link to view the complete script in a TXT format

                STAR TREK: THE NEXT GENERATION 
                              
                           "Genesis" 
                          #40277-271 
                              
                          Written by 
                         Brannon Braga 
                              
                          Directed by 
                        Gates McFadden 
THE WRITING CREDITS MAY NOT BE FINAL AND SHOULD NOT BE USED
FOR PUBLICITY OR ADVERTISING PURPOSES WITHOUT FIRST CHECKING
WITH THE TELEVISION LEGAL DEPARTMENT.
Copyright 1994 Paramount Pictures Corporation. All Rights
Reserved. This script is not for publication or
reproduction. No one is authorized to dispose of same. If
lost or destroyed, please notify the Script Department.
                         FINAL DRAFT
                       JANUARY 7, 1994
            STAR TREK: "Genesis" - 01/07/94 - CAST 
                STAR TREK: THE NEXT GENERATION 
                           "Genesis" 
                             CAST                               
                              
                PICARD             BARCLAY
                RIKER              OGAWA
                DATA               DERN
                BEVERLY            
                TROI               
                WORF               
                GEORDI             
                COMPUTER VOICE 
    
                Non-Speaking       
                  N.D. SUPERNUMERARIES
            STAR TREK: "Genesis" - 01/07/94 - SETS 
                STAR TREK: THE NEXT GENERATION 
                           "Genesis" 
                             SETS 
            INTERIORS                  EXTERIORS
          
            USS ENTERPRISE             USS ENTERPRISE
              BRIDGE
              SICKBAY                  SHUTTLECRAFT
              TEN FORWARD
              DATA'S QUARTERS
              WORF'S QUARTERS
              ENGINEERING
              JEFFERIES TUBE
              TROI'S QUARTERS/BATHROOM
              OBSERVATION LOUNGE
              SHUTTLEBAY
              CORRIDOR
              READY ROOM
              TURBOLIFT
              SHUTTLECRAFT
     STAR TREK: "Genesis" - 01/07/94 - PRONUNCIATION GUIDE 
                STAR TREK: THE NEXT GENERATION 
                           "Genesis" 
                          
                      PRONUNCIATION GUIDE 
                CYPIRION           sigh-PEER-ee-on
                SYMBALENE          SIM-buh-leen
                URODELAN           your-oh-DEE-lun
                ONGILIN            on-ZHIL-in
                SELAR              sell-AR
                HACOPIAN           ha-COPE-ee-un
                INTRON             IN-tron
                AUSTRALOPITHACINE  ahs-trah-low-PITH-uh-seen
                PISAURIDAE         piss-AR-ih-day
                T-CELL             TEE-sell
                PROTO-MORPHOSIS    pro-tow MORF-us-suss

Click this link to view the complete script in a TXT format