"Necessary or not I think we'll go anyway." Zack barks in agreement. "This big dork will worry himself sick if we don't." The Arcanine snorts at being called a big dork. But no time for arguing. Let'sgolet'sgotlet'sgo!

She's just going to climb on Zack's back. No way she's going to try to keep up on foot since he's likely to run off if he hears or smells something that could lead them to the missing Pokémon.