"Terra Incognita" is the 20th episode of the fourth season of the American television drama series Person of Interest.
The series revolves around a computer program for the federal government known as "The Machine" that is capable of collating all sources of information to predict terrorist acts and to identify people planning them.
The title refers to "Terra incognita", which is Latin for "Unknown land", a term used in cartography for regions that have not been mapped or documented.
According to Nielsen Media Research, the episode was seen by an estimated 9.21 million household viewers and gained a 1.5/5 ratings share among adults aged 18–49.
In 2008, rookie Carter (Taraji P. Henson) is partnered with Detective Raymond Terney (Al Sapienza) to investigate Chase Patterson's (Zachary Booth) family's murder.
Reese (Jim Caviezel) is notified by Fusco (Kevin Chapman) of the death of two Brotherhood members at the hand of an Elias ally.
Finch (Michael Emerson) interrupts to announce their new number: Chase Patterson, who has been suspected of murdering his family and only avoided charges when he hid in Paris.
Reese is then shot by Chase's half-brother Gil (Patch Darragh), who was the doorman at their building and is the real killer, having targeted the family after his father's abandonment.
Reese is unconvinced of both getting "happy endings" but Carter mentions his own transformation, showing that anyone can make a change.
In its original American broadcast, "Terra Incognita" was seen by an estimated 9.21 million household viewers and gained a 1.5/5 ratings share among adults aged 18–49, according to Nielsen Media Research.
And then, when he finally realized that he'd never shared himself with Carter, the scene switched back and forth in the car, from the past to the present.