/jp/ - Otaku Culture

>モー子は無意識にか、膝の上に置いたいつもの本の表紙を指でなぞる。
>それはどこか、感情を溢れさせまいとするまじないのように見えた。
In that second sentence I feel like I understood what is happening but when I looked up まじ it didn't seem to require a ない after it
But maybe what is happening here is a double negative or something