When I read Mr. Knightleys story of the London encounter between Robert Martin and Harriet I couldnīt help suspecting him of helping them along:

"It is a very simple story. He went to town on business three days ago, and I got him to take charge of some papers which I was wanting to send to John. He delivered these papers to John, at his chambers, and was asked by him to join their party the same evening to Astley's.(ch.54)

Of course he knew that Harriet was staying with his brotherīs so I guess those papers for John hadnīt been the only reason to send Robert Martin to him. And further on in this chapter he admits that he had taken some pains for Emmaīs sake, and for Robert Martin's sake...to get acquainted with her.