ふと覗くと、女の子が路地裏から出て行くところを見たんだ。

でもおかしいな……

この向こうは人の通れる隙間なんてなかったはずなのに。

I took a peek and saw a girl leaving the back alley.

But it's strange...

There shouldn't have been any gaps for people to pass through.