Harry Langford

Harry Langford is a former MI5 agent first appeared in Season 7. He later became a deep-cover agent for the MI6.

Early Life
Not much is known about his life prior to his involvement with Five-0.

In Season 8, he reveals that in his time as an MI5 agent, many years before meeting Five-0, he used to run security for The Mortimer Family. He had an affair with Lady Helen while she was separated from her husband. That romance later resulted in a daughter, Lady Sophie Mortimer. Seeing as she had decided to get back with Lord Mortimer, despite Harry's efforts to assume fatherhood, she chose to keep the baby and they agreed to lie to everyone else about her real father. This secret was discovered by Danny Williams, who recognized Harry's fatherly attitude towards her as the same he has with Grace, and his disgust regarding Lord Mortimer, as the same way he used to feel towards Stan Edwards.

Langford also said he was present when she was born and has watched her grow for most of her life. For unspecified reasons, he's lost contact with her for a few years, and said she'd changed since the last time he saw her, to which Danny replied as simply being an effect of puberty.