Have you ever heard of Marichjhapi? A tiny, little-known isl­and in the interiors of Sundarbans, about 75 km east of Calcutta? In 1979, it witnessed a macabre massacre of Bengali Hindu, mostly Dalit, refugees. It is perhaps the single largest pogrom in independent India’s history. Forty years on, Blood Island by Deep Halder vividly reconstructs the buried past of Marichjh­api. The author, a senior journalist, recorded the version of the witnesses and the survivors while investigating the massacre.

As the story begins, in the middle of 1978, around 1.5 lakh Bengali Hindu refugees started settling in Marichjhapi from the refugee camps in Danda­karanya. Most of them were Namasu­dras, the largest Dalit caste in Bengal. Driven out by the Islamists in Bang­ladesh, these Hindu refugees had cros­sed the border in search of a new home. During their stay in Danda­karanya, the Left—then in Opposition—had promised them that they would be “welcomed in Bengal with open arms” once it comes to power.

The Left...