On Guadeloupe, an archipelago in the Caribbean, the past speaks up. Sylvaine Dampierre has the workers of an old sugar refinery read passages from the transcripts of an 1842 court case, while the machines roar and groan in the background. The testimonies of the slaves from back then in the rusty halls of today give rise to a polyphony both explosive and poetic in nature. 　　The “G...