As can be seen from the earliest Sentinel cast group photos, the original concept called for four core characters -- Lieutenant Detective Jim Ellison (Richard Burgi), Anthropology grad student and Sentinel expert Blair Sandburg (Garett Maggart), Captain Simon Banks (Bruce A. Young), and Lieutenant Carolyn Plummer (Kelly Curtis), who headed the Forensics unit as well as the Technical Support unit -- and was also Ellison's ex-wife.

Plummer gave a human face to the scientific and technical resources Ellison's heightened senses would outperform. Intelligent, confident, professional and easily able to hold her own in the predominantly male Major Crime "bullpen," she was also the one person most likely to call Ellison on his unexplained ability to consistently pull forensics evidence seemingly out of thin air. There also existed the possibility that she and Ellison would rekindle their romantic relationship; despite their marriage ending in divorce, she and Ellison had obviously remained close friends. When Kelly Curtis left the show mid-way through the first season, The Sentinel continued without a permanent female character to assume Plummer's various dramatic roles.

It was not until the 1997 season that Pet Fly Productions decided to reintroduce a female regular into the cast and the dramatic roles left dormant when Curtis departed. "Dead Certain," filmed in late October 1997, introduced Cassie Welles (Lisa Akey) as the new head of Forensics. Welles would be seen in two subsequent episodes, "Breaking Ground" and "Mirror Image," after which the character was dropped.

"Dead Certain" opens with a dead body literally dropping out of the skies. Cassie Welles drops into Ellison and Sandburg's lives -- and the investigation -- almost as unexpectedly. Welles is highly intelligent and competent in her job as a Forensics officer, but she is also a frustrated detective -- her asthma barred her from that aspect of police work. Friction develops between Ellison and Welles when her desire to play a larger part in the case conflicts with his desire to run the investigation in his usual manner.

Welles uses her impressive arsenal of whiz-bang technology to identify the badly-mangled body while Ellison uses his enhanced senses and investigative skills to determine that the victim was thrown from an aircraft rather than tossed off a nearby bridge. Ellison, Sandburg and Welles each provide key clues to the unfolding mystery, which leads them to a small town outside of Cascade where the mystery is revealed -- an unscrupulous and murderous plastic surgeon operating his own little version of the federal witness protection program with assorted villains and ne'er-do-wells as clients. Welles and Ellison reach a truce of sorts after working together to capture the villains.

The episode ends with both Sandburg and Ellison turning up at a restaurant, expecting to have dinner with Welles only to find that she has deliberately accepted their invitations and set them up for a dinner for three. Welles declares that she has no intention of dating either of them as, in addition to being her co-workers, they are too competitive with each other -- thus setting the foundations for dating and competitive friction later on down the line.

(Switchman and Dead Certain "screen grabs" courtesy of Starfox and Corinna)

** Sentinel sound-stages -- "Dead Certain" -- Oct 31 '97 **

LEFT: Visits to the Sentinel sets were scheduled for days and locations where all three principal cast members would be present. More often than not, this meant the studio at 2820 Bentall Street. Visitors would be given a walk-through of the production offices as well as an orientation before being taken out to the sound-stages. The group visiting the Sentinel set in late October 1997 was able to watch Richard, Garett and Bruce rehearse and then film a number of scenes set in the Major Crime offices. Bruce, then Garett, and finally Richard took advantage of breaks in filming to come out and meet the group. The initial meeting with Richard took place outside the Major Crime set itself; the large dark expanse behind Richard is actually the photographic backdrop seen from Captain Banks' office windows. (Photo: Bert Hayling)

RIGHT: Several members of the visiting group chipped in on a very detailed and intricate miniature drum-set for Richard as a token of their appreciation for the chance to visit the Sentinel set. Richard, Garett and Bruce were largely responsible for The Sentinel's accommodating attitude towards set visits. Richard, who is an avid drummer, is seen here uncovering small parts of the detailed drum-set, which included stands for each separate drum as well as for the cymbals. He got a kick out of the miniature, as his grin demonstrates. (Photo: Bert Hayling)

LEFT: With shooting halted for scene set-ups and lunch right around the corner, Richard led the group of visitors from one Sentinel soundstage to the other and into Ellison's Loft, where he finished putting the drums together and chatted for a while. (Photo: Bert Hayling)