Although Charlotte Vale Allen’s 31st novel is one of the rare Mira hardcovers aimed at the mainstream fiction market, it has some of the qualities of the paperback category romances published by the imprint’s parent, Harlequin. So much so that the dust-jacket copy even telegraphs the genre’s inviolate happy ending by reassuring the reader that the heroine does uncover the secret of her sister’s death and “finally sets herself free from the shadows of the past.”

Rowena, on the cusp of 40, has always lived in the shadow of the beauteous but inexplicably cruel and manipulative Claudia, one of two daughters of George Graham and his ex-wife, the hard-drinking Jeanne. Growing up in this dysfunctional family, Rowena suffered doubly: her mother demeaned her while favouring her younger sister and meanwhile kept their father from seeing either of the girls. The author poses two psychological mysteries. The obvious one is whether Claudia committed suicide, an unlikely act for someone so self-obsessed, or was murdered by one of her many scorned lovers. The more diverting puzzle is why she had behaved so abominably to everyone in her life, Rowena and her mother included. The answer to the latter involves a societal problem that the ever-current Allen has researched thoroughly and presents clearly and passionately (and which can’t be discussed here without destroying much of the suspense).

In Claudia’s Shadow she also takes the huge risk of portraying a relentlessly self-hating protagonist whom readers might well have come to loathe too or, at the very least, found tiresome. Allen manages to pull it off, staying just this side of believability by giving Rowena enough grit to make her interesting. The inevitable character development arrives in time to relieve the overwhelming abasement Rowena directs at everything she is and does. Ancillary characters – among them a sympathetic gay friend and an angry girlfriend with the son Rowena never had – are well developed.

Yet early on in the tale, there are some clunky passages that seem more typical of mediocre softcover romantic fiction. When a presumably shaken Rowena arrives to identify Claudia’s body, the action stops cold for an implausibly long paragraph as the heroine describes in detail the man who ran the dead woman’s restaurant. Allen later resorts to a tired old trick that Harlequin editors have long counselled their writers to avoid: having a character describe herself by looking in a mirror.

Like most run-of-the-mill romances, Claudia’s Shadow employs a maddening failure of communication to keep the heroine apart from the hero, who in this case is the beautiful Tony, Claudia’s shrink and perhaps even lover. And it should not spoil the surprise to reveal that the novel follows hallowed tradition in having true love, in the end, triumph.