307: Exogenesis

Franklin is confounded by the death of a lurker, and Marcus is confused by the mysterious behaviour of two old friends.  The two of them venture into Down Below in search of answers, and find a group of people who have been "overtaken" by an alien parasitic implant.  Meanwhile, Ivanova attempts to evaluate the newly-promoted Lt Corwin's attitudes toward EarthGov, to determine whether or not he could be trusted should Babylon 5 go against President Clark's authority.  Franklin refuses to treat one of the infected lurkers, but Marcus' friend Duncan elects to have his parasite removed so he can tell the two of them the intent of the alien Vendrizi - to travel the galaxy and discover all its wonders, existing for perpetuity in the minds of willing hosts.  Franklin agrees to allow the Vendrizi to continue their quest provided he supervises the implantation process.  After fighting off Marcus' advances, Ivanova reluctantly recommends to Sheridan that Corwin is not involved in their plans.

Notes: Marcus receives a message from Ranger One (Sinclair), telling him that the Rangers are being withdrawn from Earth (in anticipation of the events in Point of No Return/Severed Dreams); the Shadows are gathering in Centauri space; and that a "package" is on its way from Mars - revealed in Messages From Earth.  David Corwin is promoted to Lieutenant (Junior Grade).

Guest Cast: British actor Aubrey Morris (Duncan) appeared in Stanley Kubrik's film A Clockwork Orange, and also as Captain of the Golgafrincham's "B" Ark in the TV series of The Hitch-Hiker's Guide to the Galaxy.  James Warwick (Matthew Duffin) is another British actor who appeared in the Doctor Who story Earthshock.   Carrie Dobro (Dr Harrison) later appears in Racing Mars and as Dureena Nafeel in Crusade.