The crew listens to the distress calls from the ships that Ramsey blew up. The sonar has been damaged, so the Nathan James can't tell where the sub is. The helicopter will drop passive buoys at the canal to try and find the sub. Green and his team help survivors to the shore. Sean Ramsey has sent out another propaganda broadcast claiming to be a Lt. Cdr. and in the States as an ally of the Navy, before condemning the Navy for the bombings and the spreading of the red flu.
Rachel gives Foster a checkup. Chandler visits the lab to check on the progress of the contagious cure. The new cure will only be contagious for a few days, so the crew remains booster free for now.
Slattery goes through the information Ramsey dumped -- government documents redacted to give the impression of a government conspiracy. Slattery wants to shut down the network, but Michener wants to turn it against Ramsey.
On the beach, Tex tracks the signal. but it's coming from sea.
The Nathan James isn't getting anything on sonar, but they are able to triangulate the Immune's signal with help from Tex and Danny.
The UAV approaches the source of orgin for the broadcast signal, an oil rig.
Michener prepares an inspirational video to broadcast on the network once the crew can hijack the signal.
The special ops team, lead by Chandler and accompanied by specialist officers, heads to the oil rig. The Nathan James prepares to support the team. Granderson can't find anything to power Bluetooth, and Chung says the rig has enough fuel to run for months. A girl tries to escape from her hiding spot, but is easily caught. She is Valkyrie.
"Valkyrie" is Valerie Reynolds, an engineering student from Tulane. She was aware of the spread of the virus before most, but thought it was a conspiracy. Ramsey showed her doctored documents to recruit her to his side. Chandler tries to tell her the truth, but she is resistant.
The Chief is having trouble shutting one of the last valves. Granderson can't find a key component to the bluetooth signal, so Chandler orders her to tear everything out and shut the network down.
On the beach, Flea sits next to a phone that picks up the Immune signal. He stirs up the survivors on the beach to chase Green, Tex, and Miller. They fire into the air and set off smoke grenades in order to flea to the boat. Tex is shot.
The chief continues to struggle with the last oil valve. A civilian ship approaches the rig, and as it turns, there is a man with a rocket launcher. He fires, and the chief blown up. The helicopter returns to the rig to provide support. Granderson is injured, as is Chandler. Valerie makes a break for it. The rib was destroyed, so they're stranded on the rig. The boat with the grenade launcher continues to circle the rig and fires again. Bivas, Wolf, and Burk work to close the natural gas valves. The helicopter destroys the boat. Bivas, Burk, and Wolf can't stop the gas leak. The helicopter can't land with the risk of explosion. Chandler follows Valerie, saving her. Bivas finds the "leak: at the main valve, which is open. From afar, there are several more explosions on the rig, and the antenna falls.
Rachel rushes to help the crew being brought back. The casualties are sever. Bivas is the worst off, but Burk has burns, and Chung has a brain injury which he succumbs to. Valerie watches everything in stunned silence. Chandler is hallucinating, and then collapses. He has internal bleeding and a shrapnel injury.
On the sub, Ned fills Sean in on the Valkyrie network. Sean is not upset, and is busy writing his manifesto.
On board, Rachel updates Slattery and Garnett on Chandler's progress. Bivas is still alive, but has been impaled and is not expected to survive. Wolf and Burk reassure her and hold her hands as she dies. She begins to pray in Hebrew before she stops breathing.
Rachel tends to Chandler's injuries.
Jeter leads a memorial service for the four sailors lost on the mission.
Valerie expresses her admiration of Chandler's actions to him. she admits that she was wrong to trust Ramsey. Chandler asks if she can help them.