A 10-page Special Report on Nigeria will appear in The Times on Monday. Less than three years since the Biafran secession move collapsed the Nigerian civil war has been largely forgotten. Wole Soyinka, Africa's leading playwright, for whom it remains a vivid memory and who was imprisoned for nearly two years in solitary confinement, talks in the report revealingly about his country and his own future. Peter Hopkirk reports on the mood today among former Biafrans, and Cyprian Ekwensi, the novelist, writes on Africa's "rediscovery" of its cultural heritage.