The intrigue at Highbury : or, Emma's match / Carrie Bebris.

Enhanced descriptions from Syndetics:

Mr. and Mrs. Darcy are looking forward to a relaxing stay with dear friends when their carriage is hailed by a damsel-in-distress outside of the village of Highbury. Little do the Darcys realize that gypsies roam these woods, or that both their possessions and the woman are about to vanish into the night.   The Darcys seek out the parish magistrate, who is having a difficult evening of his own. Mr. Knightley and his new wife, the former Miss Emma Woodhouse (the heroine of Jane Austen's Emma ) are hosting a party to celebrate the marriage of their friends, Mr. Frank Churchill and Miss Jane Fairfax. During dinner, Mr. Edgar Churchill, uncle and adoptive father of the groom, falls suddenly ill and dies. The cause of death: poison.   When the  Darcys and the Knightleys join forces to investigate the crimes, they discover that the robbery and Edgar Churchill's death may be connected. Together they must work to quickly locate the source of the poison and the murderer's motive--before the killer can strike again.