For an intelligent, acute thing like Locke, all it took was a curt sniff of the area for him to discern the musk of flame and perfume of water. To him, the difference was as stark as day and night to those with sight. With a hint of instruction from Iris, there was no hesitation at all before they were moving in the right direction, after the fading end of the trail. Though it may have been a challenge for the average pokemon, this was far from the first time the notorious scent hound had backtracked something.
With Iris limping and Locke blind, their pace was much slower than a younger pair would have been able to manage. Fortunately, it wasn't as if either one cared about breaking land-speed records. Both were well aware of the other's hindrances, as well as their own. As such, a meandering stroll was perfectly fine to each of them.
The closer they got to the lake up ahead, the antsier Locke's behavior became. His anxious circles and pauses didn't escape Iris' attention either, drawing the neutral corners of her mouth downward. Typically only two things caused this reaction in the meek old boy: humans and/or pokemon. The notion of a great deal of either up ahead concerned Iris quite a bit. Not only could they be a potential threat or annoyance, but too many scents could disorient poor old Locke and cause him to lose the faint trail.
"It's alright, Locke," She assured him, her whisper making his ears twitch. "You've taken us far enough for now; we can pick up again if it's safe enough.." She knew this area from visiting Lake Valor in the past -- and she owned a map, like any sane traveler -- so she was well aware of the possibility the lake had simply attracted tourists, being a site of myth and mystery. If this was the case, she would be more than willing to go around.
Before she would consider putting the extra strain on her leg, however, she had to see for herself if it would be safe to just go straight through the open landscape around the lake. Going in a direct path would make keeping track of the scent much easier.
As such, for the time being she pulled Locke's pokeball back out, returning the uneasy creature to his safe haven. Easily popping it back into its place on her cane, she half-limped her way towards the break in the foliage that spilled out into the landscape surrounding the pristine body of water. Every other step was a tad unstable and slightly louder than its more precise twin footfall, but there was nothing she could do about it. Still, only the most acute ears out there would be able to hear her muffled footsteps this far back, so she wasn't too concerned. Very carefully, she maneuvered herself to get a look at what was out on the lakeside, staying safely amongst the trees and brambles, out of direct sight.