Mistletoe and Murder by Robin Stevens

Daisy and Hazel are getting to spend Christmas is in Cambridge.  The boy's hall is much more exciting but they're not allowed in very often.  When one of the twin boys dies, they are determined to find out why.

Simon and Schuster Books for Young Readers and Edelweiss allowed me to read this book for review (thank you).  It has been published so you can buy a copy now.

The boy who died was not the one expected.  They thought the other one was being endangered.  Then the second one died.  Who killed them?  Who thought they would get the inheritance?  And when they know the answer, will they survive?