Description: Father Brown visits student Jacob Francis at the family home as Lady Felicia is worried about him. Jacob's father died a year earlier, a presumed suicide, but Jacob is sure that he was murdered and has built a time machine in which he claims he can travel back to prove the case. His other relatives are cynical though his vision of the near future seems to be accurate. But when Jacob also dies Father Brown suspects that his theory was correct and tries out the time machine for himself. Lady Felicia asks Father Brown to speak to the nephew of a family friend, 22 year-old Jacob Francis, who she describes as manic depressive, obsessive and delusional. The young man's father Frederic died a year ago, an apparent suicide, but Jacob is convinced he was murdered and says he can prove it. Jacob now lives with his aunt and uncle, Georgina and Arnold, and their two daughters, Sarah and Angelica, but spends most of his time in his laboratory working on his time machine. He believes his uncle Arnold killed his father to inherit his half of the estate. After a second death however, it's left to Father Brown to take a spin in Jacob's time machine to identify the killer.