They’re not just for Halloween anymore. Expensive, realistic masks — the kind that are the hit of the costume party — are increasingly being used out of season, and not always for laughs.

The first presentation of its kind, “New African Masquerades” offers a rare look into contemporary West African masquerade.

This story appears in the April 2012 issue of National Geographic magazine. In the realm of the spirit world, the mask is more than mere facade. It is utterly transformative. The man in the mask ...