Unable to deal with her feelings, Anna tells an unhappy Robin that they're going on a trip to New York.  Anna's decided to leave Port Charles and start anew in New York. However both fight when Robin whines "I don't want to go to New York, " and her mum replies "You're acting like a spoiled little brat!" Both burst into tears.

Meanwhile, both Duke and Camillia stand trial in L'Orleans, Canada. Jake, serving as a counsel advisor to their lawyer, tells them,  "With any luck you'll be free to go," but Camillia feels horrible after Duke replies, "Nothing matters without Anna."  Jake's prediction proves true, as the judge has to let them go since there are no witness to refute Duke and Camillia's claim of self dense. Evan's widow, Veronica, isn't about to let Camillia off the hook, pledging to get revenge for her husband's death. Now free, Duke takes off for Port Charles. Unfortunately, as he arrives back at the PC airport, he doesn't see Anna, who does she him but boards the plane to NY anyway. Duke's devastated when he learns Anna's gone. 

In NY, Anna and Robin put on brave faces for each other, but it's obvious both are miserable and would rather be home. Anna finally agrees to send Robin home after overhearing Robin crying on the phone to Filomenia. [transcript] Anna stays behind to talk to the Commissioner (played incidently by John Ingle), who gladly agrees to help her PI application approved in a week. Robin arrives home and presents Filomenia with a present, soaps and shampoos from the hotel she & Anna stayed at. 

Later, Filomenia show Duke one of the soaps, saying with a knowing look that she promised Anna she wouldn't tell Duke where Anna was staying.  She never said a word, a thankful Duke responds. Anna returns to room to find Duke there, and furiously orders him out. [transcript] A determined Duke refuses to give up, managing to get a seat next to Anna on the plane, where he spends the hour flight pleading his case to an unforgiving Anna.  Duke continues to beg for another chance but a stubborn Anna informs him, "I've only loved two men in my life. Sometimes I wish there was only one."

Secrets at HTI
Back in Port Charles, Sean becomes intrigued with geneticist Dr. Greta Instrom, who's husband Eric went missing.  Through a hostile takeover, Sean gains control of the HTI, a financially troubled research firm that the WSB had contracted. Instrom's work involves creating a secret antidote to the DVX's lethal germ MOX 36. Tiffany immediately picks up on Sean's attraction to Ingstrom, which was unfortunate for him since she, along with the various Quartermaines, is a stock holder.  Wolfgang's also a partner. Incidents cause Sean to rightly suspect the DVX is trying to infiltrate his company and destroy or steal Greta's work.

Greta's astonished when she's cornered by slimy researcher Malcolm, who's working for the DVX. He tells an that he knows that she's secretly working on the MOX formula which could be an antidote for germ warfare.  He also informs her that he stole her radioactive isotope and sold it, depositing the money into a bank account, thus implicating her in illegal activities if she doesn't go along with his demands.  She tries to stall him until she can figure out a way to deal with him.  Meanwhile, both Sean and Edward are getting suspicious that something isn't right at HTI.  

Since Tiffany's still smarting from Sean's obvious attraction to Greta at the tv station, she's thrilled to report to Sean that she found a large deposit slip made out to Greta.  Sean, who's got a lot of his own money invested in HTI, suspects Greta of industrial espionage and lays a trap for her.  He plants a "top secret" envelope for Greta to find, but Malcolm gets to it first and makes a copy of the fake data before Greta comes across it.  When the unsuspecting doctor does see the envelope, she doesn't realize it's been tampered with and has her assistant Connie return the envelope to the main office.  Once Sean learns the phony papers have reached the DVX, he immediately confronts Greta, who claimes it must have been Malcolm.  

Greta Stabbed
With Malcolm's help, DVX moles infiltrate HTI and cause Greta to go on the run. Sean and Frisco follow, catching up with the group at Niagra Falls.  On one of the Niagra Falls tour boats, Malcolm's caught up with Greta, stabbing her.  Frisco jumps off the helicopter ladder and finds her just as she collapses in his arms.  Sean follows, radioing for help as he holds Greta in his arms.  

Frisco searches the boat for Malcolm, but the DVX finds Malcolm first and kills him. Greta's wisked off to GH where Monica saves her life. A jealous Tiffany realizes just how deep Sean's feelings for Greta are as he refuses to leave her side, though he claims he only has professional interests in Greta.  Monica too notices Sean's attachment to Greta, and warns the wounded scientist to not fall in love with Sean, as he only likes damsels in distress and is incapable of sustaining a real relationship. Take it from someone who knows, Monica advises.

Sean and Frisco deduce there's a leak at HTI, which Greta confirms by telling Sean that Alistair works for the DVX. At the same time, Alistair's off to Port Charles to steal Greta's note and MOX formula, then plans to kill Greta and Sean. Sean replaces the formula with a fake one, but Roger Barrett breaks into Greta's safe and realizes the formula's a fake.  Roger's DVX too, and contacts Alistairs about the switch. Sean and Frisco finally figure out that the plant is wearing a disguise of sorts, as he/she has somehow changed their appearance. 

Taking employee cards from several years past, the duo scan and examine fingerprints of HTI employees, fnally figuring out that Roger Barrett, Greta's replacement, is the DVX plant. Sean tracks Barrett down to GH where, when he's unable to get to Greta, Barrett holds Sean and others captive in the cafeteria, threatening to kill everyone with the deadly MOX nerve gas. Frisco figures out what's going on in the cafeteria and, as Tom Hardy talks over the AP system to distract Barrett, Frisco breaks in. Barrett however takes Bobbie hostage and forces her and Sean into the elevator. Sean's then able to overtake Barrett, but both Barrett and Bobbie are accidently stabbed with the MOX formula. Rushed into the emergency room, both are critically ill. Greta treats them both with the antidote, but Bobbie's left with paralyzed.