In the series' pilot episode, Las Vegas private eye Dan Tanna (Robert Urich) is hired by a couple from the Midwest to locate their runaway daughter, who has turned to prostitution to make ends meet. When the girl winds up murdered, Tanna must follow clues into her seedy underworld. Meanwhile, at the Desert Inn, resort owner "Slick" Roth (Tony Curtis) hopes Tanna can nail a cunning trickster who has been making a killing at the casino's slot machines.
A model who is doing a shoot at the Desert Inn decides that it's time for her to quit but her manager, who's worried about losing his meal ticket, resorts to drastic measures. He hires two guys to pretend to be cosmetic executives and at the meeting they drug her and take naked pictures of her. The next morning she calls Dan who picks her up and brings her back to the Desert Inn. He asks Two-Leaf to take care of her while he looks for her manager. The manager is met by the two men he hired who want in on the million dollar contract he told her of but he says that he made it up, they shoot him. Later they send her the photos they took, along with a contract they want her to sign. Dan tries to find them but she decides to give them what they want so no one else will be hurt. When Dan learns that she went to meet them Dan and Two-Leaf go there and grab them and make them turn the negatives over.
A glittering jewelry convention at the Desert Inn attracts many buyers and sellers to the dazzling array of pricey gems...as well as some cunning thieves who plan to rob a wealthy Sheikh of his collection of valuable rubies. When Tanna gets drawn into the case, he encounters a seductive woman who may be involved in the caper.
An obnoxious and tempremental tennis player is about to have a grudge match with a rival at the Desert Inn. Now he has been receiving phone calls threatening him unless he throws the match. His manager hires Dan to protect him but he feels that his manager is overreacting. And Dan doesn't want to work for someone as obnoxious and inconsiderate as him and was about to quit when some men beat him up. Dan decides to look into it further and discovers that his girlfriend is involved with the man behind everything. When they try to get her he lets her go away. Later, his sister is kidnapped and he agrees to throw the match. Dan deduces that either the manager or the promoter is connected to the man, so when he goes to his office to find the sister, he subdues the man and his henchmen and discovers that it's the promoter. He finds the sister and arrives just in time to let her brother come from behind.
Someone is killing prostitutes, and the police are baffled. A prostitute who is a friend of Dan's is cautioned not to work but feeling that he already got his mark will strike so soon. At the police, a man named Phillip Grayson, an amateur criminologist, arrives who says that another prostitute will be killed before sunrise. And it was the one Dan spoke to earlier. He says that they are dealing with someone who is emulating Jack the Ripper, because each of the victims have the same name of the Ripper's victims. After stating that the Ripper's next killing will not take place for another month, they feel that they have time. But Grayson and Dan suspect that he may be losing touch with reality and will not wait for the month to carry out his next killing. Valerie, a policewoman and friend of Dan's, suspects the same thing so she sets herself as a prostitute with the name of the Ripper's next victim. Dan finds her and backs her up. What they don't know is that he is already there, hiding
Leon Hazlet, an Olympic gold medalist and a friend of Dan's, is paralyzed. Paul Baker, an entertainer sponsors a telethon for but Leon doesn't exactly want to have anything to do with it. Dan convinces him to make an appearance. After Paul performs someone kidnaps him and demands $250,000 but it seems that Paul doesn't have that kind of money right now. Leon offers to pay the ransom. While waiting for the kidnapper Dan calls Paul's wife and plays a tape of the kidnapper and starts to talk to him, which means that she was in on it. It seems that she's tired of being Paul's wife. Leon, who dropped the ransom and was left in the desert by the kidnapper but who managed to hang on to the van. Dan arrives to take out the kidnapper and Paul's manager, who is also in on it, with Leon's help.
A girl whom Dan is seeing is killed. Dan goes all out to find out who killed her. After talking to a friend of hers, she is killed also. Dan surmises that the only thing that they have in common is that he was with them before they were killed. Initial investigation shows that the girls struggled with their attacker which leads Dan to think that the killer might be a woman. But when Angie is also attacked she says that the one who attacked her was a man. When the attacker makes another attempt, Dan chases him and discovers that it's a woman whom he knows and it appears that she has a fatal attraction for him.
Dawn Peters, a girl whom Two-Leaf knows comes to Vegas to do a favor for someone. While having a drink in the lobby, a man approaches them and goads Two-Leaf into a fight. Dawn lets Two-Leaf rest and places the knife that he carries with him on the table. She then makes a phone call. The next day she is dead, killed with Two-Leaf's knife and he has some scratches on his face. Nelson has no choice but to arrest him. Dan doesn't believe he's guilty but still has to prove it. Dan learns that she went to a Dr. Barrow, who tells her that she came for a vitamin shot. Merrill Wayne, a television reporter has been painting Two-Leaf in a bad light. When Two-Leaf watches her, he loses it. When a guard tries to calm him, Two-Leaf knocks him, takes his uniform and gets out of the jail. Dan learns that Dawn was once a call girl so he goes to where she worked and talked to the man in charge Shining. It seems that Dawn worked there before he joined and that she called to talk his partner who died rec
Roth is talking with a man named J.T. Rodmore who gave him a tape which Roth doesn't want made public and in exchange for that Roth signs control of his empire to him and he leaves town. Dan arriving to see Roth, finds Rodmore and is incredulous that Roth would leave town without telling him. Dan then goes to everyone who saw Roth within last 24 hours and learns that it was during that time that Rodmore met with Roth. Dan learns that Roth went to Washington and has been seen all over the place but in places that he doesn't normally go to. Dan notices that someone has been following him and it seems to be someone working for Rodmore. A woman who knows Roth arrives with a message from Roth, who then calls him to back off and to get her to the airport. Rodmore tries to grab her but ends up getting her hurt. Later that night, Roth walks into Dan's place and tells him that Rodmore is his brother. It seems that his brother was originally going to go into politics but Roth's line of work made
Sarah Bancroft, a swimsuit designer, is planning to launch her line at the Desert Inn. She hires Dan, because it seems that her models are being terrorized. Dan begins by interviewing a girl who had a car accident; he also meets an old girlfriend, Holly, another model, who saw a man through a pipe on them. Dan goes to see Manny the mechanic, and learns that her car was tampered with. Later, there's a fire at the photo lab of Tom, Sarah's nephew, the photographer. The man fearing that Holly might recognize him kills her. Sarah considers canceling the show but Tom convinces her that they should go on. Tom goes to see the man, and his boss, George Crowley. It seems that Crowley is suppose to arrive at the Desert Inn with two million in diamonds. It seems he wants security concentrated at the fashion show, and his man will rob him of the diamonds, and he will then file an insurance claim and blame it on the inadequate security. When Crowley fears that Dan is getting too close, they try to
A man steals a toxin from a medical research facility, then proceeds to infect Tanna with it. Dan, after feeling a little uneasy, decides to go to the doctor, who tells him that Dan's infected with a toxin and that he is going to die. The man calls and taunts Dan. He intially suspects a man named Cruger, who he sent to prison, but he tells him that he has nothing to do with it but is looking forward to seeing Dan die. He also tells him where he can go to find some of the answers he is looking for at the Nevada Research Center, because the man who did it called him. When Dan gets there, the doctor in charge of the project tells him that unless they get back the toxin so that they could make an anti-toxin, Dan has very little hope. Dan suspects that a doctor named Durand, whom he sent away for making bogus cures and medical treatments. But Nelson tells him that Durand is still in prison but when they get there, they discover that the man whom the prison believes to be Durand is not Duran
The hotel's comptrollers call Dan and inform him that they have taken in more chips than they dispensed. And it seems that they have taken about two million. With no plausible explanation, Dan decides that they have to close the casino until they can find one. One of the hotel's executives recalls that Clay Sumner, the man who makes the Roth hotel's gambling chips, had a robbery last year but Nelson, who was called in, says that only 50,000 was taken and Dan recovered them. They then go to see Sumner and ask him if he had another robbery but says that after the robbery he redesigned the whole system and the door to the work plant has only one key which he wears around his neck. One of the employees Eddie Stolvak, who sees that Nelson is there goes to see what's going on. Nelson then decides to interview all of Sumner's employees, after Nelson leaves, Dan talks to Clay and he is still mourning his son, Brad, who died recently. Eddie then goes to see Brad who is alive and has a copy of t
Justin Marsh, who was once a great race car driver, and Dan's friend is in town for a classic car auction. Wells Tate, a mechanic, who works on Dan's T-Bird was found dead and it seems that he was planning to call Dan but was killed before he could. Dan then notices that a woman is following Justin and when he confronts her, she tells him that Justin Marsh is working for a man named Rollins who smuggles drugs into the country in classic automobiles. And buy the cars at auctions. And it seems that Wells Tate was their buyer and when he refused to continue doing it, they killed him. Dan after doing a little investigating, agress to help her, after nailing Rollins, Dan goes after Justin, Justin tries to get away but Dan chases him and Justin drives his car off a cliff.
When a friend of Dan's who's also a P.I. is killed, his girlfriend asks him to look into it. At the same time, there's a P.I. convention going on at the hotel and some other P.I.s are getting killed. A female P.I. knows something but she's not willing to share it. When an attempt is made on her, she reveals that she and other P.I.'s were hired to solve a case that's been unsolved for years.
Binzer sees a hypnotist, Paula Conway to help him. But instead she has been prepping him to kill someone for two men. When Dan, who hasn't heard from for days goes looking for him. He meets an old friend, Paula Conway, a reporter, who is in town to interview a star basketball player about point shaving but he refuses to talk, for fear that the men behind the scheme will come after him. When Binzer surfaces, he has no idea of where he has been for the last few days. Paula then sends him to steal some plastic explosives and some other materials needed to make a bomb. The men who hired Paula are also the men behind the point shaving. They are going after Paula and the player. Now after giving Binzer, his final instructions, one of the two men shoots her so that she can't call him off. Dan catches him before he could get away. Dan deduces what they are up to and forces him to tell Dan what's going on. Dan manages to get to Binzer before he could set off the bomb.
Mitch Costigian, Dan's Army buddy who's been away for sometime returns to town to perform at the hotel. He's also a newlywed. When he and Dan go to the hotel, his wife stays behind to fix things at the house. Later someone plants an explosive and blows the house up. Mitch is devastated. Later Dan learns that the explosive used is similar to what was used in Vietnam. So Dan thinks there may be a link to their time in Vietnam to what happened to Mitch's wife. Mitch is on a mission to find the one who killed his wife.
Roth is planning to put a hotel casino in Toronto and to help him with financing, he organizes a consortium of businessmen. But they're having a hard time on deciding who should be in charge. Roth wants Paul Bracken, one of his people and Dan's brother in law to be the one. But one of the members of the consortium, Mel Brandon, wants to be the one in charge. So sets out to make Paul undesirable by going after Dan and everyone around him, Bea and Binzer.
Dan decides to go to San Francisco and is shunned by the police department but decides to investigate nonetheless and sees the women and later learns that they're cops who were sent by his friend's boss to keep an eye on him. Their boss wants Dan to leave but upon learning that he made some discoveries decides to let Dan stay.
Some men try to rob the hotel but something goes wrong and they take some the showgirls hostage and Bea who was there watching them was also taken. They hold up in a room where the cops can't get to them. The leader then demands 5 million dollars or else he'll kill one of the girls every hour. And to prove he's serious, he kills one and sends her down the elevator. Dan tries to find a way to save the girls and Bea.
Two ex-cons strong-arm Binzer for the loot from a robbery he helped them commit. Dan: Robert Urich. Vinnie: Dick Butkus. Roth: Tony Curtis. Art: Denny Miller. Nelson: Greg Morris. Margie: Cindy Morgan. Arnie: Michael Constantine.
Dan is blinded by a gunman who may have been working for the mob. Landauer: Ed Nelson. Binzer: Bart Braverman. Benton: Bill Lucking. Nelson: Greg Morris. Geades: John Karlen. Dr. Lutness: Lynne Marta. Varga: Harry Guardino.
A porno-movie producer tries to take Nelson off the streets by framing him for murder. Dan: Robert Urich. Capt. Smith: David S. Sheiner. Binzer: Bart Braverman. Miller: Simon Oakland. Beatrice: Phyllis Davis.
Ten persons are gunned down in a restaurant, and Dan is hired by a victim's widow to find the killers. Green: Paul Burke. Nelson: Greg Morris. Ann: Pamela Franklin. Binzer: Bart Braverman. Diamond Jim: Victor Buono. Beatrice: Phyllis Davis. Vance: Michael Cavanaugh.
Dan helps prevent the murder of a defector who piloted a secret plane to the U.S. Col. Vance: Peter Haskell. Nelson: Greg Morris. Binzer: Bart Braverman. Victoria: Heather Menzies. Jack: Glenn Wilder. Suchak: Chuck Hicks.
Wayne Newton (as himself) hires Dan after receiving threatening phone calls that accuse him of being an imposter. Benny: Richard Lynch. Binzer: Bart Braverman. Capt. Smith: David Sheiner. Beatrice: Phyllis Davis.
Dan's detective idol asks for help in solving the murder of a woman he followed from Paris to Las Vegas. Binzer: Bart Braverman. Peterson: Randolph Mantooth. Dan: Robert Urich. Thorton: Tony Epper. Nelson: Greg Morris.
Dan is skeptical about working with a psychic to solve the kidnapping of a teenager. Nelson: Greg Morris. Cornell: Frank Marth. Binzer: Bart Braverman. Larson: James Luisi. Beatrice: Phyllis Davis. Pierce: Tim O'Connor.
Someone posing as Dan has set himself up as a one-man judge and jury to kill criminals released on technicalities. Urich's brother Tom plays T. Errol Townsend. Ramsey: Alan Feinstein. Binzer: Bart Braverman. Lupino: Eddie Zammit. Nelson: Greg Morris.