Read it through once

“Yes. He will probably be here in a few minutes. Open the door slightly. That will do. Now put the key on the inside. Thank you! This is a queer old book I picked up at a stall yesterday—‘De Jure inter Gentes’—published in Latin at Liege in the Lowlands, in 1642. Charles’ head was still firm on his shoulders when this little brown-backed volume was struck off.”