A tiny band of West Coast Canadian indians wants a mask in the British Museum returned to them. “It would be good if getting back the mask would be precedent-setting so everybody who wants their pieces get them back. The people who live in this bucolic corner of Canada’s Pacific coast say retrieval of the mask — a beautifully carved and brightly painted crest that opens into a sullen, wide-eyed human face with what looks like sun rays protruding from around its circumference — is part of a broad effort to reverse a cultural theft by Christian missionaries and a series of Canadian governments.”