Publish and be killed

It is well known that the celebrated playwright, Sheridan Seymour, had three children by his mistress. The copyright to his plays was left to his legitimate daughters, but over the years Baba, the youngest, has gained sole control. Now Sheridan's work is enjoying a popular revival on the West End stage. Baba is rich and planning to write a biography of her father, promising salacious revelations. When Tessa Crichton is asked to help prevent the biography's publication, she needs no encouragement. With all of her customary curiosity she burrows deep into the family secrets. But she is brought to a halt by the disappearance of a family member, identified as the body found in a burnt-out house - but who reappears from an impulsive visit overseas. So who died in the fire?