To everything there must be an end. And the gritty Prime Suspect series is no exception to that rule. After six electrifying cases (which aired here in the States on PBS' Masterpiece Theatre), Prime Suspect, created originally by Lynda LaPlante, concludes its run with one final installment, the aptly titled Prime Suspect 7: The Final Act.

I've followed the evolving career of Detective Superintendent Jane Tennison (the glorious Helen Mirren) for the last decade and a half or so, through the gripping and haunting series of Prime Suspect miniseries, as Jane entered the police force as a woman in a man's field and was forced to not only hold her own but prove herself over and over again a thousand times a day. A lot has changed in TV Land (and I'd like to think the world) since Jane first started flashing her badge and chasing down the baddies, including the rise of the police procedural on American television and a thousand permutations of CSI and Law & Order, but it's also seen the success of female-led policing dramas like Crossing Jordan, Close to Home, and Cold Case, series where female cops and the colleagues who love them (or love to hate them) owe a great deal of their success to Jane Tennison and her ilk.

While it's 2006, Jane hasn't stopped having to prove herself ... at least to herself or, she believes, to her dying father Arnold (Frank Finlay), whom she believes never wanted her to be a cop. (In a bit of a neat twist, he wanted Jane to be an artist, but she, as they say, couldn't help but see the skull beneath the skin.) After a career successfully nailing the perp and working her way up the Thin Blue Line to Superintendent, Jane is on the brink of retirement, but it's clear that she's sacrificed her entire life for her grueling job; it's so sad to me to see how someone with such an understanding of human nature could be so confused about her own. Jane is alone, scared, and prone to starting the day with a tall glass of vodka, neat. She's in denial about her alcoholism and has no one to turn to, and things have gone from bad to worse when she begins experiencing liquor-fueled blackouts.

This new development couldn't have come at a worse time for Jane, as she's just landed an extremely high profile and crucial case: the stunning and surprising disappearance of an angelic 14-year-old named Sally Sturdy (Maxine Barton), who might not be quite the angel everyone has made her out to be, especially when her corpse is found on the Heath. Everyone's a suspect: from the missing girl's creepily grieving father, Tony (Gary Lewis), who displays shades of Leland Palmer, to Sally's possible boyfriend Curtis Flynn (Heshima Thompson), a youth connected to several rape and murder cases, to Sally's headmaster Sean Phillips (Stephen Thompkinson), who happens to be the father of Sally's friend Penny (the incandescent Laura Greenwood), a witty and adorable girl whom Jane quickly takes a shine too.

(Personally, while I'm suspicious of Headmaster Phillips and wish Jane had taken Tony's theory a little more seriously, it's Phillips' wife Linda -- played by Eve Best -- that seems to be causing some alarms to go off in my head. Something's not entirely right there.)

It's Jane's newfound friendship with Penny that casts an unexpected dimension to Prime Suspect 7: The Final Act. It's almost as if, for the first time in her life, Jane has found a kindred spirit. It makes sense that it would be a teenage girl who has managed to breach Jane's formidable walls; thanks to the imminent death of her father, Jane has been taking a long, hard look back at her life and she sees Penny reflected there, an intelligent, gifted girl. Unlike Jane, Penny WANTS to be an artist (her father would prefer her to be a teacher), and the two bond when Jane takes Penny to see the painting of "The Strawberry Girl" at the National Gallery. (Penny is also inhumanly forgiving, as this happens after an incident in which drunk-as-a-skunk Jane nearly kills them both while driving.) But while Penny might yearn to be an artist, she too is connected to death and decay like Jane, through her relationship to the dead Sally and to the deadly secrets she seems to be concealing.

Much of Prime Suspect 7 deals with those secrets that everyone seems to keep, from teenage secret crushes and adult regrets, to the more serious consequences of hidden pregnancies, alcoholism, and cancer. Everyone in this series is living a double life or at least paying penance for the life they led. None more so than Detective Bill Otley (the late Tom Bell), the misogynistic cop longtime viewers will remember from the very first Prime Suspect. He made Jane's life a living hell those first few cases and now, with Jane about to retire from the Metropolitan Police force, he reappears like a ghost in Jane's life, offering apologies for the way he behaved all of those years earlier. And, scarily, it's Bill whom Jane most identifies with, especially after running into him at an Alcoholics Anonymous meeting.

It's Bill Otley who bookends the chapters of Prime Suspect, showing us just how far Jane Tennison has gone and reminding us of how much further she still needs to go. And while this might be the Final Act of Tennison's career, no one will walk away from this case unscathed or unchanged. Least of all Jane.

Prime Suspect 7: The Final Act concludes this Sunday on PBS' Masterpiece Theatre. Check your local listings.

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Jace is an LA-based television development and acquisitions junior exec who watches way too much television for his own good and would love a TiVo for every room in the house. (He’s halfway there.) His blog, Televisionary, can be found at televisionary.blogspot.com.