Father Frank Dowling is a priest with a penchant for solving mysteries. He has to solve the mystery of a young man who's obsessed with finding his natural parents: when the man steps out onto the ledge of a building, threatening to jump unless he's told who his parents are, Father Dowling is called to try and talk him down; unfortunately the man falls, and it looks like he may have been murdered.

A mystery man dies in Father Dowling's confessional. Frank calls the police, but when they arrive the body is gone. Investigating, Frank discovers that the FBI is somehow involved. A two-part mystery.

A woman of the parish tells her fiancé of her past as a call girl, and is promptly murdered. It's up to Father Frank and Sister Steve to discover whether it was the fiancé, or perhaps a former client, who killed her.

Sister Steve's ex-boyfriend, Jack, witnesses a murder; but when the cops arrive the victim is alive and well. Jack seeks out Sister Steve for help.

Father Dowling is caught up in a bizarre mystery when he attempts to prove a fellow priest, a guest at the Rectory, innocent of murder. In the first of a two-part story, he makes the startling discovery that the young priest's family is connected to organized crime.

Undeterred by appearances, Father Dowling sets out to prove the young priest innocent of murder, discovering he has been framed by a member of his own family. But when the real assassin is himself killed, Frank must rely on a family member who is afraid to tell the truth.

When the good Father's evil twin brother Blaine (Tom Bosley in a dual role) shows up unexpectedly, Frank suspects right away that Blaine is up to no good. After thwarting his brother's attempted diamond heist, Father Dowling finds himself in hot water when he discovers the police can't tell the two brothers apart.

A distraught woman leaves her baby at the church. Father Frank and Sister Steve track her down, but things don't add up: when they find the woman, she claims she never had a baby.

Father Dowling and Sister Steve are taken in by a fake priest. "Father" Damon is actually a hit man, apparently sent to kill aging mob boss Victor Malko. Father Dowling tries to warn Malko, but he won't take the warning seriously. And in consequence Father Dowling's own life is in jeopardy.

An exotic dancer confesses to Frank that she saw something she shouldn't have, at the nightclub where she works, then turns up murdered. Sister Steve becomes a card dealer in the nightclub to look for clues.

Sister Steve's brother Mark witnesses a murder, but the police accuse him of the crime. When Mark tries to finger the real killer — Police Chief Hayton — he may become Hayton's next victim.

Someone is shooting everyone who was associated with the Gallagher trial, eight years previously, in which Father Frank was a principal witness. But Frank isn't convinced it's Gallagher.

Father Frank's crooked twin is at it again. Frank gets involved when the woman his brother Blaine has conned turns up dead.

A parishioner is being haunted by the ghost of her dead father. Frank, Steve, and even Father Prestwick, get involved in trying to find out who is terrorizing the woman — and why.

Sister Steve witnesses a bank robbery by a supposedly blind man who she has befriended, and becomes an unwitting accomplice in his scheme to blackmail a prominent parishioner.

A black man visits Father Dowling's church claiming to be an Angel. He says someone is going to be taken before their time, and that it's up to Frank to prevent it. Frank thinks it has to do with a parishioner who owes a favor to a crime boss. James McEachin as Michael Moore.

A young couple's marriage is on the rocks when the wife is sure her husband is cheating. When she turns to Frank for help, the husband swears he isn't having an affair, but he can't disclose what he has actually been up to.

A con artist has his eye on a valuable church receptacle that Father Prestwick is taking to Romania; he'll stop at nothing to get his hands on the monstrance, even if he has to permanently inconvenience Prestwick. It's up to Father Dowling and Sister Steve to put a cap on the con.

Sister Stephanie is entrusted with six million dollars in the will of a deceased parishioner. Everyone, including the man's family, wants the money — and may be willing to do anything to get it.

A mysterious thief is methodically stealing the art treasures that once belonged to the wealthy Cabot family, and Father Dowling has an inkling the thief might be the surviving son, Jonathan. The only question is, why would a rich businessman take the risk of stealing the paintings when he could easily afford to buy them outright?

The church has hired an eccentric painter to retouch the frescoes. He turns out to be an abusive drunk and Sister Stephanie has no patience or pity for him, as he reminds her too much of her own father. But she and Father Frank must come to his aid when his studio blows up.

Sister Stephanie trades places with her double, Lady Cara (also played by Tracy Nelson), a minor member of the British Royal family, who is visiting Chicago with a trade delegation headed by David McCallum, unaware that Cara is the target of a mystery assassin.

While Father Dowling is in the hospital for minor surgery, he becomes convinced that the patient in the next bed has been murdered. While investigating, he uncovers a much bigger secret.

When most people look at Harry Deil, they see one of the most powerful men in underworld crime. Father Dowling sees something even more sinister: the Devil. Father Dowling must beat him at his own game in order to save the soul of Sister Steve.

A showy showgirl in a shady nightclub is surprised to discover her late husband's estate consists of nothing but debts. Or is she the victim of a scam to deprive her of a small fortune? The investigation reveals a motley crew of underworld suspects for Father Dowling and Sister Steve.

Guest stars: Bill Macy

Hollywood is shooting a new TV show at the church, in which a priest and a nun solve crimes. When a series of life-threatening accidents occur, Father Dowling and Sister Steve are enlisted to assist in the investigation.

Sister Steve's return to her convent to celebrate the Mother Superior's silver jubilee should be a time of great joy. But shortly after arriving, she discovers a nun with a gun, who turns out to be an undercover FBI agent. When the agent is found murdered, an innocent man is wrongly arrested for the crime.

Father Dowling is invited to a murder mystery weekend at the home of a famous mystery writer. His investigative skills are put to the test when their host himself is murdered.

Guest stars: David Warner

Father Dowling is serving as a juror, but has doubts about the testimony of a witness. Dissatisfied with the questions the District Attorney has failed to ask, Frank sets out to re-investigate the case himself, sending Sister Steve undercover in the witness's business, a New-Age bookstore, to learn what he's hiding.

Father Dowling stumbles into a kidnapping plot when he befriends a young woman, the heiress to a large brewing fortune, who promptly disappears. Fearing the worst, Sister Steve signs on as the family's new maid to try to find out what happened to the girl.

Following a murder attempt on a woman who has left her child in the temporary care of Father Dowling, the search for the assassin leads to a department store on Christmas Eve.

Trouble for Father Dowling when his evil twin brother reappears. Blaine impersonates Frank to frame him for a bank robbery, turning Father Dowling himself into a fugitive. Blaine has the perfect alibi: he's in jail, on a minor charge. The only way for Frank to clear his name is to masquerade as his brother, in order to track down Blaine's underworld associates.

Father Dowling and Sister Steve are caught up in a battle of the bugs, when warring exterminators clash at the Rectory over franchise rights. The plot is thickened by a fake Nun (with mob connections) who is calling herself "Sister Steve", a real hitman (intent on murdering "Sister Steve"), and a mobster who will do anything (even endanger the real Sister Steve) in order to save his daughter.

Sister Steve disguises herself as a call girl to track down a missing witness who can clear the name of a young businessman charged with murder. But was he really framed, or is he actually guilty? Father Dowling is uncertain.

A man Father Dowling has never met turns up at the Church, claiming to be his son, but disappears before Dowling can question him. Then his would-be son is charged with murder.

A contract killer has a change of heart when he discovers the intended victim, Father Dowling, is a priest. He warns Frank that someone else is certain to accept the contract. Now it's up to Father Dowling to figure out who wants him dead, and what their interest is in the photos he took at the parish picnic.

When a rooftop sniper almost kills Father Dowling, Sister Steve goes undercover as a cab driver, hoping to flush out the would-be assassin.

Guest stars: John Astin

While visiting the Chicago Museum to take in a new exhibit, Father Dowling and Sister Steve encounter an ancient Egyptian curse. Father Prestwick becomes its next victim when he attempts to uncover the deadly secret of the Pharaoh's burial chamber.

Father Dowling and Sister Steve go out on a limb when she kidnaps a chimp accused of murdering an animal activist. The "killer" chimp will be put down, unless they can prove it has been framed.

An author who used Father Dowling and Steve as characters in his murder mystery novel (they appear in flashbacks as the hard-boiled characters in the book) dies without completing it. Frank is sure the novel is based on a real crime and contains a clue to its solution.

Guest stars: Kevin McCarthy

Father Dowling is in Los Angeles on the trail of a runaway teenager, who's taking a walk on the wild side of L.A.'s night life.

It's difficult to tell who's consulting with who when Sherlock Holmes comes to the aid of Father Dowling. The pair prove an unbeatable team, when they put their powers of deduction to the supreme test, as eyewitnesses to multiple murders. There's only one snag: no one other than Dowling can actually see Mr Holmes!

The local District Attorney's office is home to bullets and ballots as deadly rivals battle for power. One man is already dead and an innocent boy has been charged with murder. Father Dowling tries to expose the real killer before a political rally becomes a blood bath.

Guest stars: Bruce A. Young