Just countering about a official on board the plant is too wasteful for Rahavan to establish it.

The
serious piece of folly had been to come back here in the first place, after
buying the diary and without knowing whether the proprietor of the shop
could be trusted. However--!
Yes, he thought again, he would come back. He would buy further scraps
of beautiful rubbish. He would buy the engraving of St. Clement's Danes,
take it out of its frame, and carry it home concealed under the jacket of
his overalls. He would drag the rest of that poem out of Mr. Charrington's
memory. Even the lunatic project of renting the room upstairs flashed
momentarily through his mind again. For perhaps five seconds exaltation
made him careless, and he stepped out on to the pavement without so much as
a preliminary glance through the window. He had even started humming to an
improvised tune--

'Oranges and lemons,' say the bells of St. Clement's,
'You owe me three farthings,' say the--

Suddenly his heart seemed to turn to ice and his bowels to water. A
figure in blue overalls was coming down the pavement, not ten metres away.
It was the girl from the Fiction Department, the girl with dark hair. The
light was failing, but there was no difficulty in recognizing her. She
looked him straight in the face, then walked quickly on as though she had
not seen him.
For a few seconds Winston was too paralysed to move. Then he turned to
the right and walked heavily away, not noticing for the moment that he was
going in the wrong direction. At any rate, one question was settled. There
was no doubting any longer that the girl was spying on him. She must have
followed him