'Person Of Interest' Season 4: Ep 22: 'YHWH' Recap: Will Jim Caviezel's Reese Stop Samaritan?

The Season 4 finale of Person of Interest is finally here on CBS. In Episode 22, as the war for supremacy between two Artificial Intelligences heats up, will Finch (Michael Emerson) and Reese (Jim Caviezel) meet the winner of the battle, who will call itself the deity known as, "YHWH?"

Power surges have been growing as Samaritan has discovered The Machine's location. Root (Amy Acker) smashes the wall with a sledgehammer and picks up the phone. The Machine is sending Harold a code to tell him it's dying. Elsewhere, Dominic (Winston Duke) tells Reese he wants to the key to the city and orders Fusco (Kevin Chapman)'s death. 

Harper uncuffs Fusco before Dominic's assassin can carry out the order. Control (Camryn Manheim) realizes no report has been filed for Washington, D.C., as if Samaritan is hiding its prominent attack. Control's signature has been forged to order out a quarantine. 

After Dominic ties up Harper, he orders Fusco to be shot on sight. Root and Finch enter a building, take the elevator, and interrupt a gun smuggling deal. Root and Finch try to hijack a compression algorithm but are stopped by security. 

Finch gets the algorithm from a student he saved before. With the guns pointed at Elias and Harper, Reese has to make a call to Harold. Dominic tells Harold he has to go to to a location in 15 minutes. After debating with Root, they steal a police van. 

The Machine sends Reese a message on how to fight back against his captors. Just as Reese breaks free, Fusco arrives with the calvary and arrests Dominic. Control discovers Samaritan's agents have been building a bomb, which could take out an entire federal building. 

Elias is also taken under custody while Fusco and Reese say their goodbyes. Root and Finch make a run for it as Samaritan's agents start shooting at them. Control meets with the senator and tells him Greer used them for his power play. After the senator refuses to go back to The Machine, Control has successfully cloned his cell signal. 

Reese tells Iris (Wrenn Schmidt) she needs to leave the city. He promises to tell her everything if he survives the night. Control meets with Greer (John Nolan) and holds him at gunpoint. Reese finally shows up at the location with Root and Finch. 

In the backseat of the police van, Dominic and Elias are hit with a speeding truck. With Samaritan's agents outside, Finch discovers The Machine uploaded itself into the nation's electrical grid. They can save The Machine and use Caleb's algorithm to squeeze it back into a homemade computer.

Control promises to hide Greer where Samaritan can't find him. She discovers Samaritan is planning to attack the Supreme Court. While Control's men tires to find the bomb, Finch has a chance to rebuild the Machine if they survive . 

Reese steps outside and shoots down Samaritan's agents. After Finch pulls the switch, Dominic and Elias have escaped. Control realizes the bomb wasn't at the Supreme Court. Elias and Dominic are murdered by Samaritan's agents, including Control's henchmen.

Before going offline, The Machine tells Finch that it is sorry and it failed. "Thank you for creating me," it says. Finch electrocutes itself to save The Machine.

Greer tells Control she has failed and has her taken hostage. Finch wakes up and realizes the Machine has been safely stored. Running on double AAs, the three go out shooting their way through Samaritan's agents. 

Readers, what did you think of YHWH?