Victim Card Guess - Team MbD / Lillelara / TA:
Since Agatha Christie has recently been observed visiting Scotland Yard (and we know she's not the suspect), I think it just might be possible she's been asked to identify one of the victims as Mrs. Oliver. Of course, the identification might have come out as a negative, but then again ... it might not.
So I (too) am going with this as a victim guess, with Ms. Christie's own One, Two, Buckle My Shoe
, which I just finished listening to, and which happily fulfills all three tasks of this particular card.