Family feeling; Joan Juliet Buck watches a BBC mystery about a sticky boyfriend wreaking havoc, and meets a rowdy new clan on Showtime.(Secret Smile)(Brotherhood)(Television program review)

Byline: Joan Juliet Buck

Secret Smile, a nice paranoid little mystery on BBC America, begins with a family in front of a plaque that says miranda jane cotton, 1974-2005. A dead heroine gives that extra torque to any story, and the show fairly careens through the London landscape of Miranda's life from the skating party where she hooks up with Brendan, a tall, flirtatious Scotsman-or is he a looming, leering creep?-until the end, which the BBC did not allow me to see so I wouldn't ruin the suspense.

Miranda, an architect who likes her wine, falls into bed a little too easily with Brendan, who immediately commits the fatal sins of needy creepdom: helps himself to keys, lets himself into her flat, reads her diary, is tetchy when she's late for lunch. Terminal glue. She dumps him, but within minutes he's become her sister Kerry's new boyfriend, and then Kerry's fiance, and they move into Miranda's neat little flat because Brendan is between jobs. Then he bonds with her bipolar younger brother. Miranda watches in helpless fury as her quick little misadventure takes over her family's affections, and when she tries to speak out against him she only sounds like a hysterical, jealous spoilsport.

The first half of Secret Smile, adapted from a novel by a husband-wife team who write as Nicci French, does a deft job with shifting perceptions. When does a nice, open, available, handsome man with a lot of free time stop being a catch and become an invasive, unemployed menace? The fine-featured actor David Tennant (who's in Harry Potter and the

Goblet of Fire) manages a shimmering performance between Byronic brooder and utter psycho.

Miranda is played by Kate Ashfield, who has a wary European face that could be German, Czech, or French, contradicted by a stiff bob bleached a borderline shade of pale. The hair color tells you everything about Miranda's penchant for coarse choices.

The garbage problems of Providence, Rhode Island, are a million miles away from your consciousness right now, but the people at Showtime are hoping that by the end ...