Deducing Tragedy Part Three: Hear No Lullaby

The pawns are in place and the game has only just begun.
An invisible war wages the streets of London and it’s up to Sherlock to end it.
But every step towards the end is a step away from Hanna.
Can the Consulting Detective save both, or will Eva’s game force him to do the unthinkable:
"What’s happening to us?"
"...I- I don't know and that truly terrifies me."