What is the first connection in book between Mr Hyde and Dr. Jekyll?

The first connection between Mr. Hyde and Dr. Jekyll in the book "The Strange Case of Dr Jekyll and Mr Hyde" is the witnessing of Hyde's brutal attack on a young girl. This occurs in the second chapter, titled "Search for Mr. Hyde," where the lawyer Utterson sees Hyde trample a young girl in the street.

Here's what happens:

* Utterson, concerned about Jekyll's connection to Hyde, is walking home one night when he sees a small, stooped figure brutally trampling a young girl.

* Utterson intervenes and confronts the figure, demanding his name. The figure reveals himself as Hyde, who then gives Utterson a cheque signed by Jekyll.

* This incident raises Utterson's suspicions and sets him on the path of investigating the connection between Jekyll and Hyde.

This incident is crucial because it:

* Introduces Hyde as a violent and malicious character.

* Establishes the connection between Jekyll and Hyde through the signed cheque.

* Starts Utterson's investigation and sets the story in motion.