YHWH (Person of Interest)

"YHWH" is the 22nd episode and season finale of the fourth season of the American television drama series Person of Interest. It is the 90th overall episode of the series and is written by Dan Dietz and executive producer Greg Plageman and directed by co-executive producer Chris Fisher. It aired on CBS in the United States and on CTV in Canada on May 5, 2015.

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. A team follows "irrelevant" crimes: lesser level of priority for the government. However, their security and safety is put in danger following the activation of a new program named Samaritan. In the episode, the team races to find the location of the Machine as Samaritan starts spreading power outages throughout the country to reduce its power. The title refers to "Tetragrammaton", the four-letter Hebrew word יהוה‎ (transliterated as YHWH) for the name of God.

According to Nielsen Media Research, the episode was seen by an estimated 8.18 million household viewers and gained a 1.1/4 ratings share among adults aged 18–49. The episode received near universal acclaim, with critics praising the acting, action scenes, pace, directing, writing and set-up for the next season.