While it might not have been a good idea to madly dash to the castle, in hindsight it ended up being a smart decision. Because of his decision to book it, Joel was getting close to his goal. While his time in the coal mines didn't make him an Olympic level sprinter, he was both scared out of his mind and desperate. That was a combination that tended to get people to push past what they felt was their physical limits. So while his lungs were starting to feel like they were on fire, fear for his life kept him going...and that was before he noticed the strange things prowling the streets. 

Joel was lucky that the first one he saw was looking in the opposite direction, so it didn't see him. Now while he didn't know what it was or what it wanted, he was alone and afraid, so his mind went in a rather predictable direction. '[color=fff79a]they must be after us[/color]' was what he thought. Indeed, it was rather suspicions to see more the one humanoid figure walking what were otherwise empty streets, as Joel had made sure to avoid the more densely populated ones. Had circumstances been different, he might have fought them, in order to strike back against the fear that had gripped his heart. However, he wasn't cornered enough to overcome the desire to run to the castle.