Exhausted from travel mishaps, the four return to Oxford, where the head porter Billings feeds them and sees the women safely home. The next morning, Ramy presses for action while Victoire outlines a plan: contact Hermes, gather incriminating information, and behave like overworked students. They agree on a simple cover that Lovell is ill and quarantined in London; Robin will brief Mrs Piper and raid Lovell’s office.

Robin lies to Mrs Piper about a contagious illness and a doctor’s care, accepts her comfort, and leaves fearing he may never see her again. He then breaks into Lovell’s office, pockets war-planning correspondence, and, while leaving, overhears Mrs Lovell seeking missed payments from Playfair. Seeing Lovell’s tearful children, the young son meets Robin’s eyes and says “Papa,” sending Robin fleeing.

That evening, with Hermes still silent and nerves frayed, Ramy insists they attend Babel’s mandatory garden party to keep up appearances. The event is lavish and stifling; Letty struggles, Victoire drifts, and Robin is cornered by Professors De Vreese and Playfair. Playfair exposes their cover by noting Lovell’s Hampstead house is empty and then claims he is with Hermes.

Testing him, Robin mentions Griffin’s “Canton plot.” Playfair bites, revealing ignorance. Robin improvises a trap: a supposed midnight meeting with Hermes in the Taylorian tunnels and claims to hold documents. Playfair departs, apparently satisfied, while Robin signals the others and they slip out, fearing imminent arrest.

On the street, as they debate where to run, Anthony Ribben steps from the road, alive, counts them, and orders them to follow, upending their assumption of his death and offering a sudden path forward.