Arthur doesn't like to worry about people. It's not that it's an unknown emotion - after all he had spent two years worrying endlessly about the Cobbs, both living and dead, but it's something uncomfortable. Worry implies that there's nothing he can do, and Arthur is, if nothing, a doer. So while this may be a terrible idea, he does it anyway.

In his hotel room in London, he gets comfortable in a chair; lucid dreaming happens in chairs, not in beds, in beds he doesn't dream at all. He pockets his totem and rubs the track marks on the inside of his wrist - old scars, hidden by a watch, but the signal to his body is familiar and warm. Time to go under. Time to dream.

He finds Zatanna's dream quickly enough, and watches for a moment, taking time to walk through the streets of a city he's never seen before. Where is Zatanna, here? Is she in an apartment? The dreamer appears wherever the subject is, usually, and he adjusts his tie with secure fingers and begins to look for her.