Carrie Wells seems like a typical girl living in Manhattan, volunteering at a nursing home and living her life as usual. But there's more to Carrie than meets the eye. As a young girl Carrie was diagnosed with hyperthymesia, a rare condition that makes her memory so flawless that she can't forget anything. She remembers every person she has met and every place she has been, every conversation, every moment of joy, every heartbreak – except for one day: the day her sister Rachel was murdered. When a homicide case reunites Carrie with her ex-boyfriend and partner Al Burns, she decides to permanently join his unit despite her conflicted feelings and try to solve Rachel's murder. Because all she needs to do is remember.

Once Carrie is working as a cop again, she must help a little boy who witnessed his parents' murder. Thus, she has to put aside her memories about her past and her sister to help him remember who was the killer.

Carrie tries to uncover the truth when a hotel maid (Maria Ortiz) accused of murder says she was defending herself against attempted rape.

Carrie's memory becomes crucial when a crime scene is destroyed in an explosion, moments after she catches a glimpse from the place. They discover a plot involving prison inmates and the kidnapping of a little girl.

When Al's ex-partner is gunned down and the investigation reveals he may have been a dirty cop, Carrie must decide how to support him without getting too close. Al is in danger when he is lured to a trap, and his life is in Carrie's hands.

Carrie and Al uncover a web of lies when a murder victim's identity is put into question. They find out she had no records until 18 months ago.

When a single dad is killed, Carrie races to find both the killer and the man's daughter. Meanwhile, her search into Rachel's killer goes ahead, when her mother gives her a clue.

When a public defender is murdered, the team finds out the killer may have greater plans in mind, which may lead to another murder.

Al and Carrie investigate the murder of a teen who seemed to have no enemies. Meanwhile, Carrie looks to her estranged aunt for help with the investigation into her sister's murder.

When investigating on a gang related crime scene suddenly gunfire goes off and a second murder occurs. Al and Carrie have to go through hundreds of bystanders to find out who is responsible for the killings.

When a renowned ghost hunter is killed, Carrie and Al discover that his death may be linked to a chilling discovery he made recently. With Britt Lower as Tanya Sitkowsky.

When a construction worker with a promising future is murdered, Carrie and Al wonder if his ties to the mob were the cause of his death or an unrelated coincidence. Meanwhile, Steve Cioffi (Jackson Hurst), the son of a mob boss, falls in love with Carrie.

A routine investigation into a college student's death takes a disturbing turn for Carrie when a suspect makes a dangerous move to outwit her memory.

A serial killer with knowledge of Carrie's memory abilities taunts the Queens PD as his list of victims grows. Jane Curtin joins the cast as Medical Examiner Joanne Webster.

When a key witness in his murder case vanishes before testifying, Al scrambles to find her before the suspect walks free.

Carrie and Al are at a loss to explain how a murder victim mysteriously appeared in an empty ballpark.

Al and Carrie are forced to the sidelines by a negotiator when the father of a suspect that Roe shot takes members of the Queens PD, including Nina, hostage in a desperate quest for justice.

When Carrie's latest case is stalled by a powerful family's influence, she receives assistance from a lawyer who may be the mysterious caller who orchestrated a series of sniper attacks.

Carrie's personal and professional lives collide when her boyfriend, the son of a mob boss, is revealed to have ties to suspects in a murder investigation.

Carrie and Al must get inside the mind of a deranged conspiracy theorist before he sets off a series of bombs.

When Walter Morgan turns up dead, Carrie must locate his killer while deflecting attention from the prime suspect - her. At the end of the episode the team finds a cellphone that belongs to the Syracuse Police Department.

On the trail of her sister's murderer, Carrie returns to Syracuse, where the killer may have struck again. Things get complicated when Carrie is kidnapped. At the end of the episode Carrie finds a box with all the information about Rachel's murder.