You can now switch back to your work-in-progress branch on issue 53 and proceed with your work:

$ git checkout issue53

$ vim contact.html

$ git commit -am "done mapping the hub"

Notice in the figure below how the master branch, after deleting the hotfix branch, still points at the same place.

    **The issue53 branch moves forward independently **

NB: Since a branch is an isolated working environment, the work you did in the hotfix branch is not contained in the files in your issue-53 branch. To pull the work in requires an explicit merge of the master branch into the issue-53 branch. Preferably (my take), you can delay the integration of those changes until you decide to pull the issue-53 branch back into master (the more stable branch or least questionable branch).