"Of course! Oxfords!" cries Dennis, then frowns. "No, wait, that's not it, but it's something like -- look, there! It's just around the doodads!"

He sprints off in that direction and slides to an arm-waving stop a hairs-breadth from face-planting in the Encyclopedia Britannica. He looks along the shelf before darting across the aisle to snatch up a big red book triumphantly and wave it at Sarah Jane, beaming ear to ear.

"The Oxford English Dictionary!"