Henry de Tamble was a man with Chrono- Displacement syndrome. His body time travels especially when he is stressed.
He first met Claire Abshire on one of his time travels. The Future Henry which was in his Thirties time-traveled to the meadow where the six year old Claire plays. Part of Henry's syndrome is that he can not take anything with him so whenever he is displaced, he arrives to the time and place naked. He needed to learn how to pick locks and it was when he met Claire that He was most comfortable with. She provides the necessary stuff for him.
Claire grows up with henry popping in and out of her life. She was twenty years old when she met the actual henry de Tamble. She explained to him that she knew his disorder and that it will be his future self who will meet the young Claire. It seems that in his early (normal) years, Henry is mostly traveling to the future.
Henry and Claire got married and aside from the usual husband and wife problems, thay also had to overcome Henry's frequent time-traveling disappearances (like on their wedding day) and the fact that they were having difficulty having a baby. It seems that henry's disorder is genetic and he is passing it on to their child. Claire keeps on having miscarriages because the baby inside the womb is already time-traveling.
Fortunately they have a baby girl who also has Chrono-displacement syndrome. Henry tries to teach her all she needs to know then he suddenly has an accident and eventually dies from a shot fire during one of his time-travels. Claire tries to go on guiding her daughter through CDS and eventually, their daughter meets Henry( from the Past). Claire is in dispair that she will never get to see Henry again but in the end she sees him.