Mermagen: D'you know, without your glasses, you don't look half bad.
Hester Wallace: Do you know, without my glasses, nor do you?
Tom Jericho: It's true though, isn't it? The Katyn Massacre?
Wigram: Oh, do shut up. There's a war to win, and Stalin's helping us win it.
Tom Jericho: I like numbers, because with numbers, truth and beauty are the same thing.
Claire Romilly: Poor you. I really got under your skin, didn't I?
Tom Jericho: That makes me feel really stupid.
Hester Wallace: You're not the one with the Kestrel intercepts stuffed down your knickers.
Tom Jericho: Puck and Claire were having an af.
Wigram: Were seeing each other, as you like to put it. Seeing each other's brains out.
Chosen answer: This is not a mystery. Claire "stole them to read them" as Tom Jericho told Hester. As he later explained to Wigram, she had taken the messages to give to Puck who had the means to decipher them, and who was looking for his missing brother. The Kestrel traffic from ADU contained the names of victims of the Katyn Massacre. However, Puck and Claire were surprised by the imminent reappearance of Tom, and suddenly fled, explaining why some messages were left behind.