3-197: In the Hallway of Argyle’s Lodge XIX

The three boxes of exercise books are stacked near the Storage room door.

The book grabbed at random contains mostly mathematical scribbles, a lot of them related to large prime numbers.  To Oliver this smells of cryptographical research.

Dicard nods at Oliver’s comment; Alan grunts.

Is the next room the one on the right or the left at the end of the hallway?  In either case Oliver will be able to unlock the door, but I need to know which I’m describing.