Stephen presents his thesis to the examination board, arguing that a black hole created the universe in a Big Bang, that it will emit heat, and end in a Big Crunch. He begins using a wheelchair after his walking ability deteriorates. After the Hawkings have their daughter Lucy, Stephen develops a theory about the visibility of black holes and becomes a world-renowned physicist. Jane, focusing on the children as well as Stephen's health and increasing fame, is unable to work on her own thesis and becomes frustrated. Stephen tells her he will understand if she needs help. She joins a church choir, where she meets widower Jonathan and they become close friends. She employs him as a piano teacher for Robert, and Jonathan befriends the entire family, helping Stephen with his illness, supporting Jane, and playing with the children. When Jane gives birth to another son, Timothy, Stephen's mother asks Jane if the baby is Jonathan's, which she denies. Jonathan is appalled, but when he and Jane are alone, they admit their feelings for one another. He distances himself from the family, but Stephen tells him Jane needs him.