A crush on the curate, the secret rendezvous in the vestry, shaken faith, hypocrisy and gossip - all acted out in a cosy country setting. This is trusty Joanna Trollope turf; the very centre of Middle England.
What is it about the parish yarn that arouses our interest so? It is the lure of the dog collar, according to the novelist Wendy Perriam, who maintains that many of us - and particularly Catholics - secretly harbour fantasies about stripping a priest of his surplice. "To tell the truth," said Thea, a character in her novel, After Purple, "I didn't really fancy him as a man... It was the priest I craved - not the mortal - the friar, the confessor, and the Father... It was Ray's soul and sanctity I lusted after: the robes, the vows, the rituals...". Or as Lady Starmouth, in Glittering Images, by the best-selling Anglican novelist Susan Howatch, says: "It's the collar, of course. It makes a man seem so deliciously forbidden."
But the punishment is built in, according to Ms Perriam. Clerical sex can't be sexy, she insists: "If a priest is celibate he is full of guilt and eagerness and behaves like a 16-year-old boy." And she should know. After leaving her Catholic convent school (where she was made to wear two pairs of knickers to be "doubly safe"), she lost her faith. At 21 she went to America and consulted a priest about how to recover it. "I was very lost, very depressed, mainly because of religion," she recalled. "I thought I was damned. He [the priest] was dominant, charismatic, Father, someone who could show me the way home, or so I thought. Instead I landed up with furtive sex, lots of guilt, more misery really."
Even in her fifties Ms Perriam is still afflicted by her passion for priests. "I can't pass a confessional without having a mini-orgasm," she admits. "When I see a priest walking down the street in a dog collar I get an urge to stop him and say, `Oh Father! Pray for me.'"
Ms Rhodes saves her readers such detail. For while her novel may shock some of her faithful Songs of Praise viewers, the sex scenes are modest. "Urgent, hungry kisses", "soothing" and "stroking", "searching, finding, caressing" is about as far as she is prepared to go. "I would be hopeless at writing sex scenes and so there aren't any," she insists. "I wouldn't have contemplated doing that. I would have offended the very people I care about."
At the suggestion that we all secretly fancy our vicar, she demurred: "I never have. I wouldn't have thought so." However, she understands why some women succumb. "How often do you get the chance to talk to a man about your emotions? He comes into your life during your weakest, most vulnerable moments. He's caring, knowledgeable, supportive; he makes time for you."
With 11 years' experience of presenting Songs of Praise around the country, and as a churchgoer herself, Ms Rhodes must know more than most about the workings of a local parish. "I can understand why a priest would find himself drawn to people. He may find a lot of depth and beauty in people, despite what they've been through. In a way it's surprising it doesn't happen more rather than less often."
Ms Rhodes' motives in writing The Trespassers appear entirely honourable. As a Christian mother of two, she has an unswerving belief in fidelity. "One of the themes that I hope comes across quite strongly is my belief in marriage," she said, embarking on an impassioned sermon on the subject. "Marriages aren't easy these days, but I really believe it's the best way you can live. There is incredible strength in marriage. It's very multi-layered. What you learn from the vicar's wife is that sexual infidelity is not enough to throw the marriage away. You are bound together through your children, your home, your friends and the future you have together. There's tremendous strength in that - you shouldn't throw it away."
Her own marriage ended three years ago when her husband of 15 years, Paul Williams, left her for a younger woman. But the divorce has not dented her belief in marriage. Asked whether she had forgiven her husband, she said softly: "I didn't ever think there was anything to forgive, really. I feel very strongly that people are just human beings, and human beings change and occasionally do things you don't expect them to do. I don't condemn him. There's nothing to forgive. There's no animosity there whatsoever."
According to the Rev Peter Owen-Jones, who has recently finished a novel about an erring curate, the reason we like reading about the clergy's sexual misdemeanours is that they make us feel better about our own. "It's a pressure valve for the sexual turmoil that goes on in everyone's head," he said. "It's very easy for priests to be sacrificial lambs. We're supposed to be holding the line. We're meant to embody stable, wholesome relationships. People are both disappointed and relieved when we don't."
Mr Owen-Jones, 40, was ordained four years ago. Before taking up his post in the Anglican parish of Haslingfield Harlton, Cambridgeshire, he worked in advertising and led "a full and colourful life". His curate character strays and pays heavily, but the account is sympathetic. "A priest without any sexual experience is very vulnerable when out in society," said Mr Owen-Jones. "The line between what is good and evil in terms of sexual preference has shifted incredibly in the last 40 years. That great public shift has isolated the Church totally. The Church has lost its imperial authority and therefore is made to look ridiculous."
Cristina Odone, former editor of the Catholic Herald, whose novel, A Perfect Wife, is published in paperback this week, said: "There's nothing we like better than someone who has fallen. Whether it's President Clinton, Bishop Casey or Will Carling, we're fascinated by the fall from grace of the great and the good. It is salt sprinkled on to an otherwise pretty bland public feast that we have to feed on."
Aside from the sex scenes, accounts of parish life have their own appeal, as Anthony Trollope understood so well. The parish is a microcosm of the wider world, where gossip is so powerful that it can drive people to suicide or into each other's arms. "Parishes are the last arenas where relationships are clear-cut - or at least are supposed to be," said Ms Odone. "Everything is done on an inter-personal, inter-faith basis. This is about people who actually smell each other's sweat, see each other's tears and possibly share each other's bodily functions. In an otherwise disconnected landscape, here is a small area where people are back to basics in terms of face-to-face interchange. The neighbours know what you are doing even before you do. That's what is so frightening."
The novelist Kate Saunders feels that Joanna Trollope's imitators - such as Ms Rhodes - are appealing to the same gland in us as Agatha Christie did. "Whatever goes on, there is an underlying order which will be restored in the end." She said: "Parish life is one of the few remaining places where we understand the boundaries of fooling about - more than priests, I might say, because if you look through their records they're absconding with parishioners right, left and centre."
Although she is a churchgoing Anglo-Catholic, Ms Saunders steers clear of ecclesiastical settings for her novels. She has no "jolly jersey Christian" characters, and could never countenance a priest protagonist. "Where I come from all the vicars are gay, which stretches the old imagination a bit," she joked. "My heroes are gorgeous, sex on legs, and - I'm terribly sorry - but slapping a dog collar on wipes off 90 per cent of their sex appeal."
Besieged as they are by the prurient fantasists of Middle England, some novelists still find it possible to keep their clerical heroes from succumbing to the sins of the flesh. In Ms Odone's novel the priest is tempted, but does not fall. "It is important for the most devout parishioner to know that their priest is not above temptation."