The Mystery of Three Quarters - UK cover reveal

Following the success of The Monogram Murders and Closed Casket, Sophie Hannah returns with her third Poirot novel, coming out on 23rd August. The beautiful cover for the UK publication of the book was unveiled on 29th March.

The plot:

Returning home after lunch one day, Hercule Poirot finds an angry woman waiting outside his front door. She demands to know why Poirot has sent her a letter accusing her of the murder of Barnabas Pandy, a man she has neither heard of nor ever met.
Poirot has also never heard of a Barnabas Pandy, and has accused nobody of murder. Shaken, he goes inside, only to find that he has a visitor waiting for him – a man who claims to have received a letter from Poirot that morning, accusing him of the murder of the same Barnabas Pandy.

How many more letters of this sort have been sent?
Who sent them, and why?
More importantly, who is Barnabas Pandy? Is he dead, and, if so, was he murdered?
Can Poirot find out the answers without putting more lives in danger?

Waterstones bookstore features an extract from the book, which focuses on Poirot himself.