Elle Newmark 
The Sandalwood Tree 

It is 1947, and Evie and Martin Mitchell have just arrived in the Indian village of Masoorla with their five-year-old son. But cracks soon appear in their marriage as Evie struggles to adapt to her new life, and Martin fails to bury unbearable wartime memories.
When Evie finds a collection of letters, concealed deep in the brickwork of their rented bungalow, so begins an investigation that consumes her, allowing her to escape to another world, a hundred years earlier, and to the extraordinary friendship of two very different young women.
And as Evie»s fascination with her Victorian discoveries deepens, she unearths powerful secrets. But at what cost to her present, already fragile existence?