Mark and Eleanor return to New York City, hoping to find a cure for a rare affliction. Naomi tries to balance investigating a brutal murder at work with raising her son Isaiah. Claire receives a devastating call from her estranged father.

Mark chases down a lead that might help him discover a cure for Eleanor. Eleanor sneaks off to Isaiah's talent show while Naomi discovers an unsettling pattern in a string of local murders.

Upon learning that Naomi is a homicide detective, Mark covers his tracks. Eleanor discovers that Isaiah is being bullied and seeks revenge. Naomi and Ben make a massive discovery. Claire is on the brink of a major breakthrough.

Mark and Zeke's celebration of the restaurant's tenth anniversary ends with an unexpected bang. Eleanor and Isaiah sneak out for a night of wonder and danger. Naomi struggles with new developments in her case. Claire makes great strides.

Mark moves quickly to clean up a mess, and Zeke gets roped in to help. Claire is hit with a major setback at the lab and Matthew proposes a solution. Naomi makes a devastating discovery that confirms her worst fears.

As Mark, Naomi and Ellie work together to make sure Isaiah has the best birthday ever, complicated feelings arise. Claire starts to form a bond with Matthew and continues down a path of no return.

The mystery of Eleanor's origin story as a vampire is revealed.

Mark goes on a date with Naomi, but Eleanor realizes his motives might not be as sincere as they seem. Naomi and her partner, Ben, close in on their suspect, Claire, who has found a terrifying new way to advance her research.

Desperate for help, Mark turns to his faith for guidance, but Eleanor decides to help him instead, risking her life. Naomi is visited at work by a formidable new Interpol agent and Isaiah gets heartbreaking news.

Mark and Eleanor turn to Claire and Peter for help, but soon realize they may have a plan of their own. Naomi and her new partner, Debra, make strides in their case, and Naomi uncovers a huge secret.