Here's the synopsis from bn.com
It’s 1895, and after the suicide of her mother, 16-year-old Gemma Doyle is shipped off from the life she knows in India to Spence, a proper boarding school in England. Lonely, guilt-ridden, and prone to visions of the future that have an uncomfortable habit of coming true, Gemma’s reception there is a chilly one. To make things worse, she’s been followed by a mysterious young Indian man, a man sent to watch her. But why? What is her destiny? And what will her entanglement with Spence’s most powerful girls—and their foray into the spiritual world—lead to?
The writing is great, and it's very well-researched. I loved it--the second one is even better and the third one is just out last week and I haven't read it yet. Best comparison would be to Philip Pullman's Amy Lockhart series, but I don't think those have magic. (Ruby in the Smoke is one in that series)