Outwardly, it might look like Laoise just hunkered down, supported herself by placing her hands on the ground, and spaced out. When her vision ends, she just shudders silently and slowly stands up. "Purple fire... a wish? A Noble Phantasm?" She definitely hopes for the latter. She doesn't want to imagine what kind of person might wish for something like that.
Again, without being able to control it, doubt assaults her mind. If that man was a Servant, there's a chance he might watch this park. They didn't feel any Servant nearby, but what if it was Archer or Caster? Indeed, another reason Laoise chose to come here was that the park would make an attractive battleground for Archer, while being a perfect environment for herself and Lancer to retaliate.
But now that she's here, it feels incredibly foolish to stand out in the open like an invitation. A participant in the War should think twice before risking an attack in broad daylight, but the park is deserted...
"...I want you to materialize." If Lancer is with her, at least, they should be able to make it through a sneak attack. If nothing else, it helps her focus her thoughts through the endless cloud of what ifs. "Um... it should be this way..." With that faint reassurance, Laoise leads the way in search of the grave she saw.