Devoted mother and social worker Christine Rees is still grieving a tragic loss when a stranger contacts her family, claiming an extraordinary connection. Is Christine hiding something from her family?

As Connor grows closer to Megan and Jamie, Christine pulls out all the stops to dispute his claim. Christine leans on Kate to find what she needs. Will deals with the consequences of his actions and gets an ultimatum from his wife, Samantha. As Megan's wedding to Gethin looms, Connor's appearance at her hen party causes tensions to rise even higher. Everything comes to a head with a pivotal DNA test.

Tensions are sky-high at Megan's wedding when Connor turns up uninvited and armed with damning information that Christine is desperate to keep hidden. Beth is adamant that the Rees' long-lost father is the key to everything, but every attempt to get information out of Christine and Kate proves futile. After Jamie tells Connor he no longer wants him in his life, Connor's attempt to mend their relationship forces Christine to show just how far she's willing to go to protect her family.

After the devastating events at Megan's wedding, Christine brings the Rees family together to make a risky pact. Driven by curiosity and suspicion, Beth follows her husband to a secret meetup. When her investigation into the Rees' father proves fruitful, Megan and Jamie finally get some answers. The walls are starting to close in on the family, as their spouses, Gethin and Samantha, grow suspicious. How long can the pact last?

When a police investigation begins into Connor's disappearance, Christine must pull off her most masterful show of lies yet.
The pressure is on. Worried that Kate could become a liability, Christine pays her a visit, and the Rees siblings come to blows when Jamie makes a rash decision. Meanwhile, Megan's new husband Gethin and Will's wife Samantha grow tired of their partners' lies.
A damning discovery in the police investigation threatens to expose everything.

The walls are closing in on the Rees family now that Will is the prime suspect in the police investigation. Christine is desperately trying to hold it together. As Beth and Joe get closer to figuring out what happened at the wedding, Megan and Jamie are forced into a confession. In the midst of everything, Christine grapples with the reality of Kayla's connection to her family and reveals a life-changing secret to the kids.