“I am going to take a heroine whom nobody but myself will much like.” So wrote Jane Austen when planning “Emma,” and David Eldridge appears to have taken a similarly high-risk route through “The Knot of the Heart,” his play about middle-class drug addiction whose heroine, Lucy, is never offstage. Although Lisa Dillon’s performance is wholly sincere, her character’s self-absorption is so complete it all but precludes audience engagement. More problematic still, the play’s staging posts through denial, degradation and blame to recovery are wearyingly predictable.

Caught in her dressing room smoking heroin, 27-year-old Lucy has, understandably, lost her job as a children’s TV presenter. Her mother Barbara (Margot Leicester) worries but promptly tells her she can come back to live with her and, in the first of many over-emphatic curtain lines, announces, “And I will never let you down.”

You don’t need a crystal ball to see that this statement might be Extremely Significant. Similarly, when Barbara is either wafting about with a social glass of red wine or breezily offering one, the fact that she, too, might be an addict is seriously over-signaled. The result is that from the word go, the audience is way ahead of the characters and action. And with almost no surprises aside from the odd self-deprecating joke, everything topples over into drawn-out, leaden-footed inevitability.

Having evidently researched both the trajectory and the treatment of drug abuse, Eldridge is overly anxious to explain. He details the stages of Lucy’s addiction — self-delusion, stealing, lies, abuse, pleading, self-abasement — with an admirable lack of moralizing. But Lucy’s worst, potentially most dramatic episodes are unseen, happening only in reported speech, which robs them of impact. And there’s an awkward sense of stiflingly good taste about the writing, exacerbated by Michael Attenborough’s patient, cleanly designed production. The intent was evidently to get away from ‘Trainspotting”-style cliche, but everything here feels so overly neat as to be unthreatening.

That neatness infects the under-characterized, schematically written scenes with outside professionals, especially the collection of one-note male caricatures, like the senior doctor whose comic naivete is wholly unconvincing. And even Sophie Stanton cannot bring life to Marina, the woman who runs the crisis center and who helps frightened Lucy to clean up her act.

In his defense, Eldridge is more intent on observing the pain inflicted on the victim’s loved ones and their possible responsibility for it; he’s attempting to focus on mothers and daughters as displayed by gaunt, distressed, fragile Lucy and elegantly dressed Barbara. But the two actresses stretch the text with pauses before and during almost every line, and the way they clutch themselves and cry is more about emoting than allowing the writing to achieve true dramatic momentum.

The climactic revelation by Lucy’s impatient elder sister, Angela (Abigail Cruttenden), arrives too late in the proceedings to provide the weight necessary to power the hopeful conclusion. From a writer as skilled and compassionate as Eldridge, the play is a major misfire, proving that good intent doesn’t always make for good theater.

The Knot of the Heart

Almeida, London; 328 seats; £32 top

  • Production: An Almeida Theater presentation of a play in two acts by David Eldridge. Directed by Michael Attenborough.
  • Crew: Sets and costumes, Peter McKintosh; lighting, Tim Mitchell; sound and music, Dan Jones; production stage manager, Tamsin Palmer. Opened, reviewed March 17, 2011. Running time: 2 HOURS, 40 MIN.
  • Cast: Lucy - Lisa Dillon <br> Barbara - Margot Leicester <br> Angela - Abigail Cruttenden <br> The Men - Kieran Bew <br> Marina - Sophie Stanton<br>
  • Music By: