Vincent Clarkson, a tabloid reporter, was first seen on-camera at Chad and Whitney Harris-Crane's December 26, 2006 wedding, where he was searching for colleague J. T. Cornell (who had been murdered, his corpse placed inside Chad and Whitney's wedding cake). Unbeknownst to all, Vincent was actually the long-lost son of Julian Crane and Eve Russell, who had been presumed to have died shortly after birth over thirty years previously, and had been masquerading in Harmony for two years as a Crane Industries employee named Valerie Davis. Vincent, who was very mentally unstable, was apparently approached at some time prior to the Harris-Cranes' wedding by his paternal grandfather, the presumed-deceased Alistair Crane, and convinced to do his bidding and terrorize Harmony's citizens, including his own family members, as "the Blackmailer."
As the Blackmailer, Vincent was responsible for many of the crimes that occurred in Harmony from late 2006 through the middle of 2007. Vincent's first acts of terror were to rape his own paternal half-sister, Fancy Crane, while on a stakeout in December and while she slept in her "Princess Room" in January; during the second attack, he also accosted Fancy's boyfriend, Luis Lopez-Fitzgerald - Vincent drugged Luis, collected some of his semen, then dressed him in the Blackmailer's costume (the first costume, which featured all-black clothing and a ski mask) and locked him in a closet before raping Fancy once more and planting Luis's semen inside of her. As a result, Luis was arrested for Fancy's rape. When maternal half-sister Simone Russell's girlfriend, Rae Thomas, figured out that Vincent had raped Fancy, he murdered Rae and framed Luis, and when a bartender named Dylan Flood was revealed to have information from Rae about the Blackmailer, Vincent murdered Dylan and set fire to his apartment, again framing Luis.
Vincent also began to blackmail Luis's sister, Theresa, who was also Alistair's "widow". As the Blackmailer, Vincent harbored a crush on one of Theresa's love interests, Ethan Winthrop, and, in order to ensure that he could have Ethan for himself, Vincent threatened to have Luis executed and reveal that Ethan had fathered Theresa's son, Little Ethan, if Theresa would not stay away from Ethan. When Theresa failed to do so multiple times, Vincent forced Theresa to marry Jared Casey, and then unsuccessfully attempted to force her to have a baby with Jared.
Theresa ultimately failed to stay away from Ethan, so Vincent blackmailed Judge JE Reilly into combining Luis's arson/double homicide/double rape trial with younger brother Miguel's attempted homicide trial. Reilly repeatedly denied the men due process, and a jury eventually sentenced Miguel to life in prison and Luis to death by lethal injection. Though Julian eventually made provisions so that Miguel would be exonerated, Luis remained in jail.
By the time Luis had been sent to death row, much of Harmony had become aware of the Blackmailer's existence and was working diligently to see Luis set free. When Fancy came close to securing a DNA match identifying the Blackmailer as Vincent, Vincent attempted to strangle his sister, and eventually murdered a psychiatrist who had treated him earlier in life so as to keep his identity a secret. Vincent also continued to blackmail Judge Reilly and the state governor so that Luis's appeals would all fail. During this time, only Sheridan Crane discovered that Vincent and the Blackmailer were one and the same; however, she agreed to keep his identity a secret as long as he brought her niece, Pretty Crane, back to Harmony so that she could destroy sister Fancy's relationship with Luis, with whom Sheridan was still in love. Vincent also convinced Sheridan to kill Theresa using the prison electric chair, but she was inadvertently saved from death by Gwen.
Meanwhile, as himself, Vincent was revealed in February to have been engaged in an incestuous, homosexual, and eventually adulterous affair with Chad Harris-Crane (who was simultaneously Vincent's half-uncle, adoptive half-cousin, and half-brother-in-law) since a time prior to the latter's trip to Rome (circa April 2006). Though Chad eventually tried to end the affair, Vincent blackmailed Chad with secretly-taped videos of their encounters, threatening to send them to his wife, Whitney. Vincent was furious when he discovered that, despite their affair, Chad had continued to sleep with Whitney, resulting in Whitney's pregnancy with the couple's second child. Also furious with Whitney for telling his girlfriend, Valerie Davis, that he had been cheating on her, Vincent engineered a scenario so that Whitney would walk in on Vincent and Chad having sex in the back of a gay bar; Whitney immediately left Chad, and Chad ended things with Vincent.
Things began to fall apart for Vincent when he revealed both of his secret identities - as the Blackmailer and their son - to Julian and Eve. Eve told Whitney that Vincent was her half-brother, and a furious Whitney told Chad, who was horrified to learn that he'd slept with his half-nephew. Despite Julian's insistence that they protect their son (and the Crane name), Eve outed Vincent as the Blackmailer only moments before Luis was to be executed (though, in reality, he had already been executed - Endora Lenox had turned back time inside the execution chamber in order to revive Luis). Luis was set free, and Vincent was arrested and placed in psychiatric care.
Under the care of a Dr. Tonia Wilson, Vincent was revealed to have been doing Alistair's bidding. Alistair helped Vincent to escape and assigned him to work with Spike to complete a hit list, though Vincent quickly discovered that he was at the top of the list. Spike attempted to kill Vincent, but Sheridan quickly arrived and protected her nephew, fleeing with him by car. Sheridan and Vincent eventually crashed near a cliff, Spike in their pursuit, and when Vincent and Spike argued, they both tumbled over the side of a cliff. Sheridan tried to hold on to both men, but could not, and when Spike revealed that her son, Marty, was still alive, Sheridan let go of Vincent in order to pull Spike up, causing Vincent to plummet to his apparent death on August 30, 2007. A few episodes later, however, Vincent was seen emerging from the ocean; he immediately headed to Valerie's home, and begin to attack her off-screen for "telling". However, at the end of the final episode on NBC on September 7, 2007, Valerie actually removed a facemask, revealing Vincent underneath and indicating that he had been Valerie all along, and perhaps had some sort of multiple personality disorder. On November 5, 2007, Vincent was experiencing what occurred to be symptoms of nausea and morning sickness. He ran a blood test on himself and found that he was pregnant. On November 22, 2007, Eve finally realized that Valerie and Vincent were the same person after having done an examination on Vincent (dressed as Valerie) the previous day.
Vincent threatened to kill them both if Eve told Julian, but he discovered that his lover and baby's mother are the same with his son, as Vincent was giving birth in Eve's kitchen. Even though Vincent now had a son, he still planned on murdering his parents, relatives, and anyone who stood in his way of revenge. Vincent then kidnapped his aunt, Sheridan Crane, planning to murder her and take over her life using a blond wig and a disguise. This eventually failed, as Sheridan survived Vincent's attempt to kill her by sending her over Niagara Falls.
After finding out that his father's penis had been severed—by a second Harmony serial killer—Vincent made sure that Eve was drunk and drugged before she performed surgery on him—causing her to reattach Julian's penis upside-down. Vincent then discovered that the other Harmony murderer, who had murdered not only Fox and Alistair Crane but all of Esme Vanderheusen's boyfriends, was Esme's niece Viki. Vincent convinced Viki to join forces with him in murdering all of their enemies in Harmony. Thus, they planned to kill everyone at the same time at a quadruple-wedding rehearsal dinner. They picked poison mushrooms off of the old wood in the Harmony wharf and cooked them into a sauce, that would be served at the dinner where everyone would be attending. Vincent disguised himself as the caterer, and he and Viki's plan succeeded as everyone at the rehearsal ate their poison mushroom sauce and died.
Tabitha Lenox subsequently gave up her magical powers to resurrect the dead residents of Harmony. Upon returning to life, Sam Bennett arrested Vincent and Viki for their crimes.