Alias

Sydney Bristow discovers that her job as an agent for SD-6, a top-secret division of the CIA, holds some deadly secrets that threaten the security of the free world. In spite of being warned against it, Sydney reveals her secret to her fiancé, Danny, who later on is murdered. Sydney finds that her father, Jack, is also SD-6 and that the group is not part of the CIA, but actually an enemy of the United States. Sydney seeks the aid of the real CIA and is enlisted as a double agent under the command of operations officer Vaughn. Her mission now is to complete her cases at SD-6 while reporting her findings back to the CIA. But when Sydney finds out that her father is also affiliated with the CIA, she begins to question where his true allegiances really lie.

Sydneys life is in mortal danger as she is sent to Madrid to retrieve a 500-year-old sketch that contains a set of numbers and meets up with her deadly nemesis, K-Directorate agent Anna Espinosa. Meanwhile, Will delves deeper into the cause of Dannys death and discovers a very strange anomaly.

Sydneys secret double agent status is jeopardized after she smuggling a biotech engineer into SD-6 from her mission in Berlin. Will meets a woman who confesses that she was having an affair with Danny shortly before his death. Vaughn informs Sydney that her father may be working for a third secret operative agency.

While helping Shepard escape from the asylum in Bucharest, Sydney discovers the shocking connection he has with her past. Meanwhile, after tracking the computer virus secretly planted by the CIA, Sloane is confronted by Alliance representative Alain Christophe, who suggests that one or more moles may have infiltrated SD-6. Will continues to investigate the woman claiming to be Dannys mistress and Sydney finds out the truth about her fathers involvement in her mothers death 20 years earlier.

Sydneys life is placed in mortal danger when Sloane is informed by his superior that she is the SD-6 mole. Meanwhile, Dixons life hangs in the balance after he is shot on a mission, and Will realizes that his discovery of Kate Jones pin could uncover some unexpected information.

Sydney is grateful and proud of her father after he saves her life while on a case in Havana. But her admiration is short lived when Vaughn discovers further evidence that Jack may have been responsible for the deaths of over a dozen CIA officers many years earlier.

Vaughn disobeys orders and attempts to help Sydney and Jack avert the destruction of SD-6 headquarters and all its occupants. Meanwhile, McKenas Cole continues his vendetta against Sloane and searches for a mysterious device. A desperate but determined woman convince Will to continue his investigation of SD-6 and the imprisonment of David McNeil.

Vaughn asks Sydney to use her friendship with Sloanes wife, Emily, to gain access to a mysterious Rambaldi book which happens to be under lock and key in a safe at Sloanes home. Meanwhile, Will is kidnapped and told to drop his investigation of SD-6 or risk the lives of his family and friends, including Sydneys.

While the FBI detains and questions Sydney about her past and possible ties to a mysterious Rambaldi doomsday prophecy, Vaughn and Jack must race to free her and find a way to clear her name before her cover is blown and SD-6 is made aware of the situation. Once the rescue op has been launched, in her quest to prove her innocence, Sydney shocks even her usually unflappable father when she makes a chilling discovery that may unravel the mystery of the 500-year-old prophecy – she finds proof that Rambaldis writings may hold more truth about an alleged weapon of mass destruction - and the fate of her own family.

Sloane begins to question where Noahs true allegiances lie, as passion ignites between Sydney and Noah. Meanwhile, Sydney continues to uncover new information about her mother, which disturbes Jack. A rogue assassin known as the Snowman is dispatched by K-Directorate to kill Khasinau, a.k.a. "The Man." Will and Francie confront Sydney about the mysterious airline ticket stub found in her jacket.

Wills life is about to change as he is sent to find the person responsible for leaking information to him about SD-6. Meanwhile, Sloane finds himself on the cusp of finally tracking down Khasinau when SD-6 captures "The Mans" right-hand man, Mr. Sark. Dixon becomes suspicious of Sydneys activities.

Sydney finds herself face-to-face with her mother, whose intentions for her daughter are made chillingly clear. Meanwhile Sydney continues her search for Vaughn, not knowing if he is dead or alive after being swept away by a wall of water in Taipei. Wills life is forever changed when he learns the truth about SD-6 and Sydneys life as a double agent. Dixon must decide whether or not to inform Sloane of Sydneys suspicious activities.

Sydney must outwit Sark in order to find a crucial piece of intel. Meanwhile, Jack faces Sydneys mother for the first time in almost 20 years. Will finally meets Vaughn and Sloane is haunted by his wifes death.

Sydney discovers a terrifying secret when shes sent on a case to track down a new generation of weapons. Meanwhile, Vaughn suspects Jack of setting up Sydneys mother to take a fall. Sloane tells Jack the truth about Emilys death.

Sydney races to find a cure for Vaughn, but in order to find the antidote, Sydney must make a deal with Sark that could endanger Sloanes life. Meanwhile, Will continues his research for Vaughn and discovers some disturbing inconsistencies involving 20-year-old standardized IQ tests.

While continuing on a mission to take control of six nuclear warheads, Sydney and Jack discover where Irinas loyalties lie when she meets up with Gerard Cuvee. Meanwhile, Sloane informs the Alliance that Emily may still be alive.

After completing his first mission with Sydney, Marshalls life is placed in mortal danger. Meanwhile, Ariana Kane suspects Jack as being the prime suspect in the disappearance of Sloanes wife. Vaughn learns the truth about Jacks involvement in the murder of CIA agent Haladki and Sydney confides in Francie about her feelings for a fellow co-worker.

Sydney and Jack are confronted by the new director of SD-6 who replaces Sloane, whose whereabouts and intentions are unknown. Meanwhile, romantic sparks begin to fly between Francie and Will.

Sydney must make a life-defining decision regarding her future with the agency, while Sloane re-emerges and continues his obsessive quest to piece together the mysterious Rambaldi artifacts - with the reluctant aid of a kidnapped scientist. Meanwhile, Dixons marriage is put to the test after he tells his wife the truth about his occupation.

Sydney begins to question where Vaughns allegiances lie when she learns through CIA Agent Yeager that he is under investigation by the Agency. Meanwhile Irina and a crucial Rambaldi manuscript are used as bait to try to catch Sloane, and Sydney welcomes Dixon to the CIA.

Sydney defies her father in her attempt to rescue a kidnapped scientist, while Sloane, seeking revenge, becomes more dangerous than ever. Meanwhile, Francie manipulates an unsuspecting Will for his agency connections.

Sydney begins to question Wills identity when hes arrested for espionage, under suspicion of being a double. Meanwhile Sark and Irina plot to recover the Rambaldi heart, and Sloane makes Jack a business proposal.

Sydney tries to piece together the last two years of her life and discovers the fates of her friends and family. She confronts Vaughn about his marriage and learns the shocking fates of Jack and Sloane. Meanwhile, she is granted temporary CIA clearance on a case that may help her regain her memory.

Sydney and Vaughn are reunited again as a team to prevent Sark from destroying the nations satellite communications system. Meanwhile, Jack must find a way to stop Marshall from uncovering the identity of a familiar murderer. Sydney accompanies Vaughn and Lauren as they meet with Sloane to ask for a favor.

While Vaughns life hangs in the balance, Lauren butts heads with Sydney after learning the part she played in his stabbing. Meanwhile, Sydney further questions Sloanes allegiances after he is kidnapped by Kazari Bomani, a kingpin in The Covenant; Jacks cover is jeopardized when he meets with Simon to dig up information on Sydneys missing two years; and Marshall is sent on his second mission with Sydney, posing as a high-stakes, southern gambler.

Jack takes drastic measures to ensure that the NSC never finds out the truth about Sydneys murder of a Russian diplomat. But his actions place a heavy strain on Vaughns marriage, as Lauren gets closer and closer to the truth about Sydney. Meanwhile, Sydney agrees to go on a mission with Sloane in order to thwart plans to obtain the operating system to a deadly weapon -- and she discovers an unlikely ally in the hunt for her missing two years.

After making a shocking discovery in the desert, Sydney agrees to submit to an experimental procedure conducted by an eccentric doctor, designed to retrieve her lost memories. But while Jack and Vaughn look on, Sydneys mind proves surprisingly resistant to letting her remember her missing time -- and the process of recovering it could end up killing her. Meanwhile, Lauren makes a great sacrifice in order to make her alibi believable to Lindsey after breaking Sydney out of NSC custody, and Sloane finds himself boxed in by an unlikely enemy -- one who wants to see Sydney Bristow eliminated permanently

Sydney finally learns the shocking truth about her missing two years from an unlikely source.

Sydney and Vaughn are sent to retrieve the Doleac Agenda to gain an advantage over The Covenant. For this, Sydney and Weiss must convince rogue security systems designer Toni Cummings to help the CIA break into a Lethal Response System. Meanwhile, Sark approaches an unlikely ally to kill the Covenants Cell leaders.

Sydney and Vaughn must convince bomb maker Daniel Ryan that they are part of The Covenant in order to find out where he has hidden one of his devices. But Sydney discovers that her ties to the bomber could lead him on a suicide mission.

Sydney and Vaughn must track Kazari Bomani down to get hold of a piece of the Rambaldi puzzle. Meanwhile, Jack reveals his suspicions to Senator Reed about his daughter Laurens allegiances, and Vaughn decides what to do about his marriage.

After finding out that Lauren is working for the Covenant, Vaughn is told to keep up the façade of a happy marriage in order to keep tabs on his wifes activities. But hes in for a shock when he uncovers the truth about Laurens mother, Olivia. Meanwhile, Jack refuses to help exonerate Sloane of his crimes and put in motion a stay of execution, and a monk discloses the identity of the Rambaldi "Passenger" to Sydney.

With the aid of Katya Derevko and CIA imprisoned security systems designer Toni Cummings, Sydney and Vaughn attempt to track down Sloane and Nadia. But Lauren and Sark are also in hot pursuit of them in order to uncover the secrets of Rambaldi. Meanwhile, Vaughns obsession with tracking down Lauren is beginning to consume him, Sydney and Vaughn turn the tables on an old foe, and Katya expresses her attraction to Jack.

Sydney quits the CIA and joins a Black Ops unit called "Authorized Personnel Only" alongside Dixon, Jack, Vaughn and... Sloane. Meanwhile, the truth Sydney found out in Wittenberg endangers her relationship with Jack, and eventually she reveals the awful truth to Vaughn.

Sydney must seduce a murderous arms dealer in order to track down a stolen NSA code-breaker. Meanwhile, Vaughn fears for Weisss life, and Sydney and Jack argue about telling Nadia the truth about her mother.

Sydney and Vaughn go undercover as a married couple so as to find a weapon that could bring back the Dark Ages. However, the neighborhood theyve infiltrated is not as charming as it seems.

While Sydney and Nadia argue about Nadias acceptance of Sloanes fatherly concerns, Sloane worries about Nadias well-being when she and Sydney go undercover as wealthy, irresponsible young heiresses to uncover the whereabouts of a deadly chemical.

While Nadia is in a coma, Sark is taken into APO to help them infiltrate Cadmus Revolutionary Front and retrieve the bomb, but in return he demands to see Laurens corpse and that Vaughn opens her coffin for him. Nadia may be the only person with the intel they need to intercept the bomb, so Jack is forced to prematurely wake Nadia from her coma, endangering her life, which doesnt please Sloane when he finds out.

Sydney must protect the life of a civilian, whom she unintentionally put in danger. Meanwhile, Jack plans a visit with an old friend, and Vaughn uncovers more disturbing secrets about his father.

When a mission goes wrong, Sydneys is placed in danger and Marshall is the only one who can save her. Meanwhile, Dixon is exposed to a deadly pathogen released inside APO.

In an attempt to talk to Sydney, Katya Derevko deliberately poisons herself and is temporally taken out from her cell. Once Nadia tells her sister about this, Sydney visits her aunt to tell her to stay away from Nadia. However, Katya unsettles Sydney by telling her that someone framed her mother as a means of getting her killed. Sydney sets off in search of the truth behind this story. Meanwhile, Vaughn becomes a rogue agent by getting involved with the people who might know his fathers whereabouts. In the end, he and Sydney find out that the man behind these two plots is no other than A. Sloane. However, things are not exactly as they seem to be.

Nadias former caretaker, Sophia, has been severely beaten. She contacts Nadia and asks to meet her. Sloane is told by Sophia that she was beaten up, because someone is trying to track Nadia down, so he and Jack decide to tell their daughters the truth – Elena Derevko, the third and the most cruelest of the Derevko sisters, has been surveilling both Sydney and Nadia for a decade. Meanwhile, Jacks doctor advises him to tell Sydney about his illness.

The team captures the Sloane Imposter and questions him to find a rare Rambaldi orchid. The real Sloane must relive a painful memory in order to get the Imposter to reveal the orchid location.

Rambaldis catastrophic endgame begins to fall into place as a giant version of the Circumference/Mueller device is found floating over city in Russia, driving the citizens made. After a wounded Dixon reveals that Irina is alive, Sydney, Nadia, and Jack set off to find her. Irina had been captured, and then duplicated using Project Helix, in order to give the impression that she was dead. Sydney and Nadia discover Irina is being held inside a camp in Tikal, safely in the clutches of Elenas army. Irina had apparently been working to counter Elenas organization, the Covenant, and actually PREVENT the Rambaldi endgame. Irina tells of a page she destroyed, a page that was key to Rambaldis endgame. Under torture, she finally broke and recreated it for Elena. After a short respite, the transport turns towards Russia, and Sydney, Vaughn, Jack, Nadia, and Irina parachute down, towards Elena, Sloane, the Circumference....and destiny.

After learning that the man she has known as Michael Vaughn is under investigation and suspected of being a double agent, Sydney begins to question whether their business and personal relationship over the years had all been a lie.

Sydney is forced to partner on a mission with new APO agent Thomas Grace. They discover that Rachel Gibson -- a spy suspected of being involved in activities against the U.S. -- has something shockingly in common with Sydney.

Sydney and Tom discover that Renie has stolen the cryo container, and soon find themselves under siege by a group of mercanaries who want the contents of the container. Meanwhile, Sloane takes matters into his own hands to get himself back into APO.

Sydney and APO attempt to discover whom Gordon Dean is working for and what their end game is. Meanwhile, when the group claiming to have a cure for daughter Nadia continues to play mind games with him, Sloane struggles for control.

Sydney teams up with Vaughn after being kidnapped and being placed in a hypnotic. What Sydney doesnt know is that the kidnapper is a very familiar face with an obscure interest in her unborn child.

Sydney gives birth to the baby, but Sloane may need something from the newborn. Nadia awakens.

While the gang starts to learn more about the Prophet 5, Sloane is distressed to learn that Prophet Fives cure for Nadia is just as likely to kill her. Meanwhile, Devlin returns, the search for Anna Espinosa continues, Rambaldis prophetic Page 47 resurfaces, and Sydney offers Renée a job at APO.

Sydney now posing as Anna, brings Peyton a microchip with a device hidden in it. Meanwhile Sloane finishes translating page 47 and reports that only the chosen one can complete the circle, which leads Sark and Sydney on a dangerous mission to a prison. Rachel finally discovers Toms secret about what happened to his wife.

Peyton tells Sloane that she has made a deal for the Rambaldi Sphere with an ally in China. Sloane arranges for stolen missiles to be sent to Hong Kong. Sloanes plan is revealed to the APO members, who race to stop him before he can use the Rambaldi Sphere to put the plan in motion. But this all leads to a long awaited confrontation between Sydney and Irina.