The Diplomat Season 3 Episode 7 recap revisited: A deadly weapon forces the White House to rethink its strategy

The Diplomat Season 3 Episode 7 is titled PNG. It came out on Netflix on October 16, 2025.

The episode continues the season’s high-stakes political drama. Kate Wyler, the U.S. Ambassador, is trapped inside Winfield House. Protests block the streets outside. The anger comes from Prime Minister Trowbridge’s shocking claim. He accuses the late U.S. President Rayburn of causing the HMS Courageous attack.

Personal problems also grow. Kate and lobbyist Callum Ellis grow close, but they do not fully trust each other. Their tension mirrors the failing alliances around them. Hal also tries to control the story and shape the narrative. The Diplomat Season 3 Episode 7 shows pressure, secrets, and broken relationships.

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The Diplomat Season 3 Episode 7 recap: PNG

The Diplomat Season 3 Episode 7 starts with the world in shock. Prime Minister Nicol Trowbridge claims the late U.S. President Rayburn helped cause the HMS Courageous attack. The accusation spreads fast in global news. Protests explode everywhere. The White House faces a huge crisis with no easy answer.

Outside Winfield House, crowds fill the streets. People shout and protest. To stay safe, Kate Wyler hides in the backseat of a borrowed minivan. Secret Service drives her through the mob. She is now the Second Lady. But she still refuses to run from her duties.

Inside the house, Kate gets a call from Billie. Billie explains President Grace Penn’s plan. Penn wants to correct Trowbridge’s false story. She will name Roylin as the real mastermind behind the attack. If Trowbridge refuses to change his statement, the U.S. will reveal the truth alone. This could push the U.K. into even more conflict.

Stuart asks Kate what really happened with Rayburn. He is confused and upset. Kate lies and says Rayburn was involved. She knows this is not true. But she believes the U.S. needs one strong story. She wants to control the global narrative before things get worse.

Meanwhile, in The Diplomat Season 3 Episode 7, Callum Ellis sneaks onto the property. He pulls Kate aside. He tells her the U.K. has found the Russian submarine. It is twelve miles off the coast. There are no survivors. Trowbridge refuses to let the U.S. near the wreck. He does not want another disaster at sea.

Callum then shares something even worse. The submarine is carrying a Russian weapon called the Poseidon. It is a nuclear-powered device. It can spread huge amounts of radioactive fallout. The U.K. cannot handle it safely. The U.S. can. If China or another country steps in, the crisis could become global.

Even with all this happening, Kate and Callum share a quiet moment. The house is empty. The stress is heavy. They become intimate for the first time. But the calm ends quickly.

Back in the U.S., in The Diplomat Season 3 Episode 7, President Penn’s team argues about what to do. Hal says the U.S. should not apologize. He thinks it will make America look weak. Billie says the U.S. must speak carefully. She wants to control the message before the world blames them for something they did not do.

At the same time, the British government cuts off contact. Stuart cannot talk to Trowbridge. London blocks every U.S. channel. No one will answer them.

Eidra brings new intelligence. Trowbridge has secret meetings planned with a Chinese nuclear and robotics expert. This means he may ask China to help retrieve the Russian submarine. If China steps in, the U.S. could lose access to the wreck. They could also lose control of the powerful weapon inside it.

Kate and Callum argue about how fast they need to act. Callum wants her to push the White House right away. He says they must face the Poseidon threat now.

Then he admits something big. He knew about the weapon months ago. Kate explodes in anger. She feels he hid the truth from her. She feels he dumped the crisis on her at the last second. It reminds her of how Hal treats her.

Callum says he was once a young soldier. His past makes him scared and urgent. But the damage is already done. Kate tells him he is “another version of Hal.” Their fight leaves their relationship unsure and shaken.

In The Diplomat Season 3 Episode 7, Kate calls Billie and Hal about the Poseidon weapon. At first, Billie does not believe it. Then she understands how big the threat is. She and Hal brief the President. Even Hal, who hated that Kate talked to Callum, knows the danger is real.

The White House still cannot reach Trowbridge. So they prepare for something risky. Kate may need to speak to the world herself. Hal strongly disagrees with this plan.

Billie quietly tells Stuart he may need a lawyer. Rayburn’s accusation could get very messy. Later, Hal tells Billie the truth. He and Kate are separated. They only pretend to be married for political reasons.

Callum later tells Kate that Grace Penn called Trowbridge herself. She offered a bilateral summit in the U.K. Surprisingly, Trowbridge agreed. This meeting may be the only way to calm the crisis in The Diplomat Season 3 Episode 7. It may also help solve the submarine problem before another country steps in.

After their fight, Kate tries to fix things with Callum. She admits she struggles to treat people the way they deserve. She asks him for a second chance. Callum nods. But it is not clear where their relationship really stands.